Fri Oct  1 19:05:04 EDT 1999  Austin Donnelly  <austin@gimp.org>

	* app/gimpimage.c: Factored out common code from
	    gimp_image_{raise,lower}_layer and
	    gimp_image_{raise_layer_to_top,lower_layer_to_bottom}.  They
	    now call gimp_image_position_layer() to do the real work.
	* app/gimpimage.h: gimp_image_position_layer() takes extra arg to
	    tell whether an undo should be pushed.
	* app/layers_dialog.c: reposition layer with undo.
	* app/undo.c: new undo type for layer reposition.  Layer rename
	    shouldn't dirty and clean the image twice!
	* app/undo.h: prototype for undo_push_layer_reposition().
	* app/undo_types.h: LAYER_REPOSITION_UNDO type.