2003-03-25  Michael Natterer  <mitch@gimp.org>

	* app/core/gimpimage.[ch]: added new functions
	gimp_image_active_[layer|channel|vectors]_changed() which emit the
	resp. signals.

	* app/core/gimpimage-undo-push.c (undo_pop_layer,channel,vectors):
	fixed them to not leave the image's active layer, channel, vectors
	pointers undefined (fixes bug #109110). Call gimp_item_removed()
	from all of them.

	* app/core/gimpimage-qmask.c: cleanup.