GtkTree update

[jrb redhat com]

I have been busy working on the GtkTree replacement.  I sent the headers
to the list a few months ago, and ended up making a large number of
changes to them (yes Maciej, the names are now a lot more explicit...)
Anyway, I would like to commit them to GTK+ soonish, so I'm resending it
to try to get any last API comments.

As the headers are largish (1500 lines), I put up a tarball at:
http://www.gnome.org/~jrb/gtktree.tar.gz

Status:

Basic Tree/List implementations exist, as well as simple
pixbuf/text/toggle renderers.  The model implementations both need to be
completed in letting the view know of updates, but they are otherwise
done.  The view is useable currently, though it needs a little support
for things like popup menus.  The following additions are needed to
bring it fully up to the clist's level of functionality:

 * GtkTreeModel needs to be changed from a model to an interface.

 * Implement reordering/alphabatization and letting the view optionally
   ref-count nodes.

 * Drag and Drop support.

 * Editting (if there is time)

 * Bug fixing and cleanup

Thanks,
-Jonathan