2003-12-09  Michael Natterer  <mitch@gimp.org>

	* app/core/core-enums.[ch]: removed enum value
	GIMP_UNDO_GROUP_EDIT_COPY (I have no idea why we used to push an
	undo group around "Copy"...).

	* app/core/gimp-edit.c (gimp_edit_extract): new utility function
	which does everything needed for cut and copy and does not push an
	undo group for copy.

	(gimp_edit_cut,copy): removed lots of duplicated code and call
	gimp_edit_extract().

	(gimp_edit_paste,paste_as_new): no need to call
	gimp_item_set_image() on newly created layers.