2000-05-28  ERDI Gergo  <cactus@cactus.rulez.org>

	* src/workbook.c: Create and insert GtkComboStacks into the
	toolbar for Undo/Redols

	* src/commands.c: Use the new undo/redo stack methods

	* src/workbook-view.[ch]: Several new methods to modify the user interface
	to the undo/redo stack