When more than 30 scenes are in a scene, the sequencer "Add" option didnt
show a databrowse window.
This was a nasty one, because databrowse facilities are more-of tied to
having a header. The fix is that I added option to IDnames_to_pupstring()
to not limit the menu (by passing NULL for menu short pointer).
Also noticed a bug with pupmenu_col(), which did return on a val==0 event
(mouse release) which shouldn't be, this makes sequences of menus not
possible.
c8cadcd557