I have implemented a fair amount of additional functionality for
todo-mode and in the process fixed several bugs persisting in version
1.50, which is the current CVS version as well as the one included in
the released Emacs 21.2.  A diff against this version and a ChangeLog
are attached below.  This patch also corrects and hence supercedes
previous todo-mode patches I posted here on 26 November 2001 and 24
January 2002 (neither has been applied to the CVS source as of today).
I've tested the changes with Emacs 21.2 and 20.7, under both X and
tty.

Since the diff is rather long, it may be helpful to point out the most
significant changes (IMO): I've added functions to rename and to
delete TODO categories, to display a clickable list of categories, to
move TODO items from one category to another, to file items within
their category and display these under their category buffer, to add a
customizable string to separate items within a category, to change the
TODO item prefix string and to toggle its display within the category
buffer.

I welcome and would be grateful for any feedback about the new
functionality and any suggestions for improving the implementation.

--Steve Berman