2002-12-29  Murray Cumming  <murrayc@usa.net>

	Fixes #102168.

	* gtk/gtkliststore.c, gtktreednd.c, gtktreestore.c:
	Actually implement the GtkTreeDragSource::row_draggable virtual
	function in GtkListStore and GtkTreeStore instead of just checking
	whether it's implemented at all. This means that DnD isn't broken by
	gtkmm's virtual function wrappers. The alternative would be to
	hard-code the TRUE return value into gtkmm's wrappers, but that's
	part of GTK+'s implementation, not it's API.