Without this patch, calls to the sorting functions from lisp did not
work as advertised.
* lisp/org-list.el (org-sort-list): Respect sorting-type and getkey-func when
they are specified in the call.
* lisp/org.el (org-sort-entries): Respect sorting-type and getkey-func when
they are specified in the call.
* lisp/org.el: Safe-guard agains the accidental loading of compiled
versions of org-loaddefs (these must be bogus). Make sure that
installations that do not have the source files (only .elc) and/or
compress the files (.el.gz, .elc.gz) are correctly treated when such
files must be loaded. If it is necessary to exclude compiled files
from loading, temporarily bind load-suffixes to only (".el") instead
of forcing a literal ".el" suffix (which doesn't work with
compressed files for some functions). Re-implement org-reload to
reload based on features that are currently loaded rather than files
it finds in whatever directory since it is impossible to know if
they were loaded from there. Indicate whether the reloading was
successful or encountered an error in the message area.
* lisp/org.el: Remove utf-8 codepoints in docstrings, bytecode doesn't
work when loaded from compressed files.
Probably a bug in Emacs, but since this is unlikely to be fixed in old
Emacsen, simply don't do it.
* contrib/lisp/org-export.el (org-export-expand-macro): New function.
(org-export-as): Use new function.
* lisp/org.el (org-macro-expand, org-macro-replace-all): Change
signature. The function now accepts an alist of templates so it
doesn't have to rely only on `org-macro-templates'.
(org-macro-initialize-templates): {{{date}}} is not anymore an alias
for {{{time}}}. During export, it will provide the value stored in
DATE keyword instead.
* testing/lisp/test-org-export.el: Add tests.
* testing/lisp/test-org.el: Update tests.
* lisp/org-src.el (org-escape-code-in-string,
org-unescape-code-in-string, org-escape-code-in-region,
org-unescape-code-in-region): New functions.
(org-edit-src-code, org-edit-src-exit): Use new functions.
* lisp/org.el (org-strip-protective-commas): Removed function.
* lisp/org-exp.el (org-export-select-backend-specific-text): Use new
function.
* lisp/ob.el (org-babel-parse-src-block-match,
org-babel-parse-inline-src-block-match, org-babel-insert-result):
Always escape produced blocks, independently on the language of the
block, if any. Use new functions.
* doc/org.texi: Update documentation.
* testing/lisp/test-ob.el: Update test.
* org.el (org-calendar-agenda-action-key): Delete an option.
(org-mode-map): Delete its keybinding.
(org-agenda-action-marker, org-mark-entry-for-agenda-action):
Delete.
* org-agenda.el (org-agenda-diary-entry): Don't prevent from
being used outside of Org agendas, as it can be used in
calendar buffers too.
Note that we may have to reimplement the functions related to
"k" in the calendar.
* org.el (org-make-link-description-function): Enhance
docstring.
(org-insert-link): Fall back on interactive prompt when
`org-make-link-description-function' fails.
Thanks to Sylvain Rousseau for triggering this.
* org.el (org-priority): Use a new argument to show priority
instead of setting it.
(org-show-priority): New function to show priority both in
normal Org buffers and in Org Agenda buffers.
(org-speed-commands-default): Use "," as a speed command for
setting priority.
* org-agenda.el (org-agenda-mode-map): Bind
`org-agenda-priority' to `C-c ,' as it was before.
(org-agenda-show-priority): Delete.
(org-agenda-priority): Use a new argument to show priority
instead of setting it.
Thanks to Robert Horn for triggering this change.
* org.el (org-font-lock-hook, org-set-font-lock-defaults): Add
a docstring.
(org-display-inline-remove-overlay): Rename from
`org-display-inline-modification-hook'.
(org-speed-command-activate): Rename from
`org-speed-command-default-hook'.
(org-babel-speed-command-hook): Rename from
`org-babel-speed-command-activate'.
* org-agenda.el (org-agenda-update-agenda-type): Rename from
`org-agenda-post-command-hook'.
(org-agenda-mode): Use the new name.
(org-agenda-post-command-hook): Define as obsolete function.
* org-lparse.el (org-lparse): Temporarily activate the hooks
needed for the ODT conversion.
(org-lparse-preprocess-after-blockquote): Rename from
`org-lparse-preprocess-after-blockquote-hook'.
(org-lparse-strip-experimental-blocks-maybe): Rename from
`org-lparse-strip-experimental-blocks-maybe'.
(org-lparse-preprocess-after-blockquote-hook)
(org-lparse-strip-experimental-blocks-maybe-hook): Define as
obsolete functions.
* org.el (org-days-to-time): Make obsolete.
(org-time-stamp-to-now): Rename from `org-days-to-time'.
Allow to compare time-stamps based on seconds.
* org-agenda.el (org-agenda-todo-ignore-time-comparison-use-seconds):
New option to compare time stamps using seconds, not days.
(org-agenda-todo-custom-ignore-p)
(org-agenda-check-for-timestamp-as-reason-to-ignore-todo-item):
Use the new function's name and the new option.
This idea came up while reading Jay McCarthy's blog here:
http://jeapostrophe.github.com/blog/2012/09/19/omnifocus-and-org-mode/
* lisp/org.el (org-format-outline-path): New argument SEPARATOR to
specify a string that is inserted between parts of the outline path.
(org-display-outline-path): New argument SEPARATOR, to specify a
string that is inserted between parts of the outline path.
* org.el (org-activate-plain-links)
(org-activate-bracket-links): Add a new 'htmlize-link text
property, so that htmlize (> version 1.42) can linkify the
links.
Thanks to Hrvoje Nikšić for suggesting this.
* org.el (org-display-outline-path): Allow a string value for
the `as-string' parameter. Such a value will replace the "/"
separator in the output.
Thanks to Sébastien Vauban for triggering this.
* org.el (org-display-outline-path): New argument `as-string'.
This useful if you want to display the outline path in the
minibuffer like this:
(add-hook 'org-mode-hook
(lambda() (add-to-list 'mode-line-format
'(:eval (org-display-outline-path nil t t)) t)))
* org.el (org-in-subtree-not-table-p): New utility function
for building the menu.
(org-org-menu): Add an item for refiling. Check more contexts
when activating items.
(org-tree-to-indirect-buffer): Use `org-up-heading-safe'.
* org-agenda.el (org-agenda-tree-to-indirect-buffer)
(org-agenda-do-tree-to-indirect-buffer): Use argument `arg'.
* org.el (org-link-to-org-use-id): Move to org-id.el.
* org-id.el (org-id-link-to-org-use-id): Rename from
`org-link-to-org-use-id'. Use `nil' as the default value.
(org-link-to-org-use-id): Alias and define as obsolete.
`org-link-to-org-use-id' was previously defined in org.el but only
active when org-id.el was loaded. This is wrong. It now belongs
to org-id.el.
Also, as some libraries require org-id.el on the fly, a non-nil
default value for `org-link-to-org-use-id' had the side-effect of
changing the behavior of `org-store-link' behind the user's back.
Which is wrong too. The new default value is `nil' so that, even
when a library requires org-id.el without the user noticing it,
the behavior of `org-store-link' will not change.
Users who want to keep the previous behavior can set the variable
to 'create-if-interactive-and-no-custom-id
INCOMPATIBLE
* org.el (org-refile-keep): New variable.
(org-copy): New command to copy notes.
(org-refile): New parameter msg to override the "Refile"
string in the default prompt.
(org-mode-map): Bind "C-c M-w" to `org-copy'.
* org.texi (Refile and copy): Document the new command `org-copy'.
* orgguide.texi (Refile and copy): Ditto.
Thanks to Kalev Takkis who triggered this change.
* org.el (org-cycle-hide-inline-tasks): New function to hide
inline tasks when cycling.
(org-cycle-hook): Use the new function.
Thanks to Christopher Witte for triggering this and to Carsten for
suggesting this change.
* org.el (org-use-last-clock-out-time-as-effective-time): New option.
(org-current-effective-time): Use the new option.
* org-clock.el (org-clock-get-last-clock-out-time): New
function.
When set to `t', this new option will take the time of the last clock out
timestamp and use it when changing/logging the todo state.
Thanks to Gaizka Villate who suggested this.
* org.el (org-link-to-org-use-id, org-directory)
(org-default-notes-file, org-reverse-note-order)
(org-extend-today-until, org-finish-function)
(org-store-link-functions): Use "capture" instead of
"remember" in docstrings. Also use the `org-capture' group
when it makes sense.
* org.el (org-create-formula-image-with-dvipng): Fixes a bug
introduced in 149cc04782 that made it
fail with no :foreground and :background attributes set, due to bad
handling of "Transparent" color.
* org.el (org-activate-plain-links): Don't try to check if we
are in a bracket link already.
This partially reverts commit ad35e2.
The problem that this commit was trying to
address needs to be rethought.
Thanks to Scott Randby for reporting this.
* org.el (org-read-date-analyze): Fix bug introduced in commit
cc5f9f: adding a time should not prevent relative answers to
be parsed correctly.
Thanks to Michael Brand for reporting this.
* org.el (org-outline-level): Go at the beginning of the
headline first to always return a sensible result.
* org-agenda.el (org-search-view, org-agenda-get-todos)
(org-agenda-get-timestamps, org-agenda-get-sexps)
(org-agenda-get-progress, org-agenda-get-deadlines)
(org-agenda-get-scheduled, org-agenda-get-blocks): Return the
correct level depending on `org-odd-levels-only'.
* org.el (org-format-latex-options): Add `auto' to docstring.
(org-format-latex): Get face colors at point and put them inside opt.
(org-create-formula-image-with-dvipng): Fix bug when colors are not
`default'.
(org-create-formula-image-with-imagemagick): Fix bug when handling
"Transparent" bg color.
(org-dvipng-color-format): Same as `org-latex-color-format' for
dvipng-style color specification.
If `auto' is used for the :foreground or :background value in
org-format-latex-options, the the appropriate color is chosen
from the face in which the formula is displayed.
This commit resurrects the `org-create-formula-image' function which was
removed in commit a9d3ce. This function is still called elsewhere, and
provides a simpler interface to the two backend-specific image creation
functions.
This also simplifies `org-format-latex', which still has some serious
problems such as optional arguments such as PROCESSING-TYPE which are
never assigned a default value, and extraneous variables.
At some point the `org-create-formula-image-with-imagemagick' and
`org-create-formula-image-with-dvipng' functions should be combined as a
great deal of code and logic is duplicated between the two functions.
* lisp/org.el (org-format-latex): Simplified and now makes use of the
new `org-create-formula-image' function.
(org-create-formula-image): Provides a simpler interface to the two
backend-specific functions.
* org-colview.el (org-columns-next-allowed-value): Add the
CLOCKSUM property to the list of properties that can be
changed interactively from the column view.
* org.el (org-entry-put): Allow to set the CLOCKSUM property
by updating the most recent clock. This is useful in the
column view when you want to use S-<left/right> to update the
last clock of the entry at point.
Thanks to Rainer Stengele who suggested something along those
lines.
* org.el (org-image-actual-width): Rename from
`org-image-fixed-width'. Update the docstring. Give more
choice.
(org-display-inline-images): Use the option new choices.
* org.el (org-image-fixed-width): New option to set a fixed
width for inline images.
(org-display-inline-images): Use the new option.
This option only takes effect for Emacs >=24.1, build with
imagemagick support.
Thanks to Alexander Willand who requested a similar feature.
2012-08-25 Michael Sperber <mike@xemacs.org>
* org.el (org-fill-paragraph): Pass optional argument to
`fill-paragraph' to fix compatibility with XEmacs.
* org.el (org-mode): Set the syntax of the " character to
"string quote".
Thanks to Samuel Wales for asking a related question and to Nick Dokos
for suggesting this solution.
* lisp/org.el (org-mode): Call external initalizers. Now both filling
code and comments code have their own independant part in org.el.
(org-setup-filling): Renamed from `org-set-autofill-regexps'.
(org-setup-comments-handling): New function.
* lisp/org.el (org-fill-paragraph): Refine filling in comments and in
paragraphs. Allow commented blank lines. Take into consideration
the indentation of the second line of the paragraph being filled.
(org-comment-or-uncomment-region): Rewrite function. Now comment
region at a fixed column: the minimal indentation of the region.
(org-fill-context-prefix): Rename function into
`org-adaptive-fill-function'. Also, In a paragraph, choose the same
prefix as the current line.
* lisp/org.el (org-backward-element): When called at the beginning of
first element in section, the function shouldn't return an error but
move point to headline or point-min instead.
* testing/lisp/test-org.el: Add test.
* lisp/org.el (org-fill-context-prefix): Fix incorrect output when
called at the beginning of a plain list with an affiliated keyword.
(org-fill-paragraph): Remove useless variable.
* lisp/org.el (org-fill-context-prefix, org-fill-paragraph): Do not
fill verse blocks contents. Verse blocks can be used to format
free-form poetry, so filling has to be done manually.
* testing/lisp/test-org.el: Remove unnecessary tests.
* org.el (org-contextualize-keys): Rename from
`org-contextualize-agenda-or-capture'. Fix normalization to
handle empty key replacement string.
(org-contextualize-validate-key): Rename from
`org-contexts-validate'. Allow checking against a custom
function.
* org-agenda.el (org-agenda-custom-commands-contexts): Update.
(org-agenda): Use `org-contextualize-keys'.
* org-capture.el (org-capture-templates-contexts): Ditto.
* org.texi (Templates in contexts, Setting Options): Update to
reflect changes in how contexts options are processed.
* org.el (org-contextualize-agenda-or-capture): Handle key
replacement depending on the contexts.
* org-capture.el (org-capture-templates-contexts): Allow to
use the context as a way to replace one capture template by
another one.
* org-agenda.el (org-agenda-custom-commands-contexts): Allow
to use the context as a way to replace one agenda custom
command by another one.
* org.texi (Templates in contexts): Document the new structure
of the variables `org-agenda-custom-commands-contexts' and
`org-capture-templates-contexts'.
In the setup below, X is not a real capture template, it is just
an alias to templates A and B in .txt and .el files. A and B are
deactivated by default in all files.
(setq org-capture-templates
'(("X" "Nothing but an alias")
("A" "AAAA" entry (file+headline [...]))
("B" "BBBB" entry (file+headline [...]))))
(setq org-capture-templates-contexts
'(("A" "A" ((not-in-file . ".*")))
("B" "B" ((not-in-file . ".*")))
("X" "A" ((in-file . "\\.txt")))
("X" "B" ((in-file . "\\.el")))))
Thanks to Carsten for suggesting this "key-replacement" idea!
* org.el (org-contextualize-agenda-or-capture)
(org-rule-validate): New functions, implement context
filtering for agenda commands and capture templates.
* org-agenda.el (org-agenda-custom-commands-contexts): New
option.
(org-agenda): Use it.
* org-capture.el (org-capture-templates-contexts): New option.
(org-capture-select-template): Use it.
* org.texi (Templates in contexts): Document the new option
`org-capture-templates-contexts'.
(Storing searches): Document the new option
`org-agenda-custom-commands-contexts'.
This idea comes from Sylvain Rousseau, who implemented a similar
feature with org-context.el: https://github.com/thisirs/org-context
This implementation is a bit simpler and more general. Simpler
because it relies on existing templates, no need to define other
contextual ones. More general because contexts can be defined
wrt files and modes.
Thanks *very much* to Sylvain for paving the way -- certainly a
great addition to Org.
* org.el (org-mark-subtree): Maybe call `org-mark-element'
interactively.
(org-mark-element): Only mark further elements when called
interactively.
For example, M-x org-export RET calls `org-mark-subtree' and
should not mark the further element when an element is already
marked.
Thanks To Bernt Hansen for reporting a bug related to this.
# Please enter a commit message to explain why this merge is necessary,
# especially if it merges an updated upstream into a topic branch.
#
# Lines starting with '#' will be ignored, and an empty message aborts
# the commit.
* org.el (org-activate-plain-links): Don't activate a plain
link when it is part of a bracketed link, unless bracketed
links are not enlisted in `org-activate-links'.
(org-open-at-point): Don't consider the text immediately after
a bracketed link is part of a plain link.
This fixes a bug when fontifying [[http://orgmode.org][Org]]Mode --
where "Mode" should not be fontified, because it is not part of the
bracketed link.
Note that there was another related bug: C-c C-o on "Mode" used to
try opening a plain link. Also fixed in this commit.
* org.el (org-compute-latex-and-specials-regexp)
(org-paste-subtree, org-sort-entries, org-store-link)
(org-open-at-point, org-file-remote-p, org-add-log-setup)
(org-set-tags-to, org-fast-tag-selection)
(org-diary-sexp-entry): Ditto.
* org-agenda.el (org-agenda-get-blocks, org-cmp-priority)
(org-cmp-effort, org-cmp-todo-state, org-cmp-alpha)
(org-cmp-tag, org-cmp-time): Remove useless (t nil) sexps at
the end of (cond ...) constructs.
* org-mobile.el (org-mobile-create-index-file): Ditto.
* org-lparse.el (org-lparse-format-table-row): Ditto.
* org-list.el (org-sort-list): Ditto.
* org-id.el (org-id-get): Ditto.
* org-html.el (org-export-html-preprocess): Ditto.
* org-exp.el (org-default-export-plist)
(org-table-clean-before-export): Ditto.
(t nil) in (cond (...) (...) (t nil)) has no other meaning that to
remind the developer that the cond sexp returns nil in case no condition
is matched. For several (cond ...) constructs this is obvious from reading
the code. For others, the reminder might be useful and we leave it.
See the discussion about this on emacs-devel:
http://thread.gmane.org/gmane.emacs.devel/152664
* lisp/org.el (org-fill-paragraph): Fix filling in a narrowed buffer.
(org-fill-context-prefix): Fill prefix doesn't depend on current
narrowing.
* testing/lisp/test-org.el: Add test.
* org.el (org-options-keywords): Add "TODO".
(org-make-options-regexp): Make the hashtag mandatory for
options and don't allow whitespaces between the hashtag and
the plus sign.
* lisp/org.el (org-fill-paragraph): No need to use
`org-element-paragraph-separate' in a verse block since blank lines
only can end a "paragraph".
* lisp/org-element.el (org-element-paragraph-separate): Apply changes
to comments.
(org-element-paragraph-parser): Correctly find end of paragraphs.
(org-element--current-element): Require colons for Babel calls.
(org-element-center-block-parser, org-element-dynamic-block-parser,
org-element-quote-block-parser, org-element-special-block-parser,
org-element-comment-block-parser, org-element-example-block-parser,
org-element-export-block-parser, org-element-src-block-parser,
org-element-verse-block-parser): Fall-back to paragraph parsing when
incomplete or ill-formed.
* testing/lisp/test-org-element.el: Update tests.
* org.el (org-read-date-analyze): Allow both "8am Wed" and
"Wed 8am" to be parsed correctly with respect to possible
values of `org-read-date-prefer-future'.
(org-read-date-prefer-future): Update docstring to remove the
restriction about inserting only the time. The user can now
insert the time and the day.
* org.el (org-fill-context-prefix): Require org-element.
(org-timestamp-change): Fix bug by saving excursion when
adjusting another clock.
Thanks to Steinar Bang for reporting this.
* org.el (org-custom-properties): New option.
(org-custom-properties-overlays): New variable.
(org-toggle-custom-properties-visibility): New command to
toggle the visibility of custom properties.
(org-check-before-invisible-edit): Also prevent errors when
trying to edit invisible properties.
Thanks to Torsten Wagner for triggering this discussion.
* org.el (org-fill-paragraph): Correctly fill paragraph in
message-mode.
(org-indent-line): Correctly indent according to mode when
`orgstruct++-mode' is on.
(orgstruct++-mode): Add `fill-prefix' to the variable temporarily
stored in `org-fb-vars'.
* org.el (orgstruct-setup): Require `org-element'.
This prevents an error for git users who use orgstruct-mode
(and orgstruct++-mode) and forget to make autoloads.
* org.el (org-forward-heading-same-level): Rename from
`org-forward-same-level'.
(org-backward-heading-same-level): Rename from
`org-backward-same-level'.
* org.el (org-forward-element): Rename from
`org-element-forward'.
(org-backward-element): Rename from `org-element-backward'.
(org-up-element): Rename from `org-element-up'.
(org-down-element): Rename from `org-element-down'.
(org-drag-element-backward): Rename from
`org-element-drag-backward'.
(org-drag-element-forward): Rename from
`org-element-drag-forward'.
(org-mark-element): Rename from `org-element-mark-element'.
(org-transpose-element): Rename from `org-element-transpose'.
(org-unindent-buffer): Rename from
`org-element-unindent-buffer'.
(org-mode-map): Update the names of a commands.
Remove useless declarations.
* org-element.el (org-element-forward, org-element-backward)
(org-element-up, org-element-down)
(org-element-drag-backward, org-element-drag-forward)
(org-element-mark-element, org-narrow-to-element)
(org-element-transpose, org-element-unindent-buffer): Move to
org.el.
* lisp/org.el (org-mark-subtree): Do not make a special case for
inlinetasks when marking a subtree. These are handled by
`org-element-mark-element'.
* testing/lisp/test-org.el: Add test.
* org.el (org-mode-map): Use `M-h' for
`org-element-mark-element'.
(org-mark-subtree): Allow a numeric prefix argument to move up
into the hierarchy of headlines.
* org-element.el (org-element-up, org-element-down): Autoload.
* org.el (org-outline-regexp-bol, org-heading-regexp): Use
variables instead of constants.
This fixes compiler warnings when compiling with Emacs 23.4.
* org.el (org-open-at-point): Only set
`clean-buffer-list-kill-buffer-names' when the feature
'midnight has been loaded.
Thanks to François Allisson for reporting this bug.
* org.el (org-special-properties): New special property
CLOCKSUM_T.
(org-entry-properties): Handle the new special property.
* org-colview.el (org-columns): Handle a new special property
CLOCKSUM_T.
(org-agenda-colview-summarize, org-agenda-colview-compute):
Ditto.
* org-clock.el (org-clock-sum-today): New function.
(org-clock-sum): New argument PROPNAME to set a custom text
property instead of :org-clock-minutes.
* org.texi (Special properties, Column attributes)
(Agenda column view): Document the new special property
CLOCKSUM_T.
Thanks to Brian Wood who asked a question wrt this.
* org.el (org-get-property-block): Find blocks before the
first headline.
(org-entry-properties): Minor code cleanup.
(org-entry-get, org-entry-get-with-inheritance): Get property
before the first headline.
* org.el (org-latex-preview-ltxpng-directory): New option.
(org-preview-latex-fragment): Store LaTeX preview images in
`org-latex-preview-ltxpng-directory'.
Added an option `org-latex-preview-ltxpng-directory' with a path
where the preview images will be stored. The default does not
change (small little ltxpng scattered all over the place) but now
the user can chose an absolute path and put all the images on a
single place.
TINYCHANGE
* org.el (clean-buffer-list-kill-buffer-names): Declare.
(org-open-at-point): Allow opening multiple shell links by
creating a new output buffer for each shell process. The new
buffer is added to `clean-buffer-list-kill-buffer-names'.
Thanks to Tobias Naehring for this idea.
* org.el (org-link-to-org-use-id): use `org-capture' instead
of `org-remember' in the docstring.
(org-link-fontify-links-to-this-file): New function to fontify
links to the current buffer in `org-stored-links'.
(org-store-link): Small code simplification.
(org-link-prettify): Enclose literal links into <...> instead
of [[...]].
(org-insert-link): Use `org-link-fontify-links-to-this-file'.
Also allow completion over links' descriptions, as well as
links destinations. When the user uses the description for
completion, don't prompt again for a description.
Thanks to Yagnesh Raghava Yakkala who suggested this.
* org.el (org-mode-map): Don't bind C-<up> and C-<down> to
`org-element-backward/forward' as these functions stops when
there is no element of the same type before/after point. It
is useful to navigate with `forward/backward-paragraph' with
no stop in most cases.
* org.texi (Fast access to TODO states): Fix documentation
about allowed characters for fast todo selection.
* org.el (org-todo-keywords): Ditto.
This fixes this wrong change here:
http://orgmode.org/w/?p=org-mode.git;a=commit;h=b6cb72
Prior to this change compiling org-mode and then running Org-mode
functions from a batch Emacs would throw the following error.
Symbol's function definition is void: org-check-version
Moving the require of org-compat before the use of this function in
org.el fixes this problem.
* lisp/org.el (org-compat): Require org-compat before we first use one
of its functions (a macro actually).
* org.el (org-speed-commands-default): New speedy command to
quickly add the :APPT_WARNTIME: property.
* org-agenda.el (org-agenda-to-appt): Use the :APPT_WARNTIME:
property to override `appt-message-warning-time' when adding
an appointment from an entry.
* org.texi (Weekly/daily agenda): Mention APPT_WARNTIME and
its use in `org-agenda-to-appt'.
This feature has been suggested, along with preliminary patches,
by Ivan Kanis. Thanks!
* org.el (org-version): Improve docstring.
(org-self-insert-cluster-for-undo): The default value should
be nil for Emacs >=24.1. See bug#11774.
See http://debbugs.gnu.org/cgi/bugreport.cgi?bug=11774 for a
discussion about this.