* lisp/org-colview.el (org-columns-summary-types): New variable.
(org-columns-compile-map): Rename into...
(org-columns-summary-types-default): ... this.
(org-columns-new):
(org-columns-compile-format): Use new variables.
* testing/lisp/test-org-colview.el (test-org-colview/columns-summary):
Add test.
* doc/org.texi (Column attributes): Document new variable. Improve
description of time and age based summary types.