2001-03-05  Sven Neumann  <sven@gimp.org>

	* app/Makefile.am
	* app/apptypes.h
	* app/gimpimage-undo.[ch]
	* app/gimpundo.[ch]
	* app/gimpundostack.[ch]: added new GimpUndo and GimpUndoStack objects
	which will be used for the upcoming new undo system. Actually my
	current plan for the undo system is to keep it pretty much as it is...

	* app/gimpimage.[ch]: added new GimpUndoStacks but temporarily kept
	old GSLists around, so I don't break everything now.