`org-publish-get-base-files-1': get the proper list of files when
recursing thru a directory.
`org-publish-get-base-files: use the :exclude property to skip both
files and directories. This might be refined when the semantic of
publishing options gets simpler, but do this for now.
`org-publish-project': removed third arg of defalias to avoid
compatibility issue for Emacs 22.1.
This required changing the Makefile.
I also added a new program set-version.pl that can be used
to synchronize the version number in all core files of the
distribution, along with the web files.