* xmenu.c (menubar_selection_callback): Force out GTK buffered

* xmenu.c (menubar_selection_callback): Force out GTK buffered
	events so the menu event comes after them.  This is to prevent sit-for
	from exiting on buffered events directly after a menu selection,
	lisp code for Help => About Emacs uses sit-for.

	* gtkutil.c (create_menus): Connect selection-done event instead of
	the deactivate event to deactivate_cb.  This will make the last
	leave event come before the call to deactivate_cb, so the leave
	event does not make sit-for exit after a menu selection.