2004-03-20  Simon Budig  <simon@gimp.org>

	* app/core/gimpundo.[ch]: Make it possible to refresh the preview
	of an undo step.

	* app/tools/gimpeditselectiontool.c
	* app/widgets/gimpitemtreeview.c
	* app/widgets/gimplayertreeview.c: refresh the preview when
	compressing undos. This ensures that the last preview in the undo
	history always reflects the current state of the image.