Menus - contolling popup/down behavior for GUI builders

[Damon Chaplin <damon helixcode com>]

What do people think about adding functions to have more control
over when menus popup/down. This would be useful for GUI builders
since we could do in-place editing of menu items.

I actually had a go at this a while back, and I think I only had
to change a few things (like removing grab_add()s). I would try
to put a patch together if it would be accepted.

(unless the functionality is already there and I missed it)

Damon