2000-04-27  Gene Z. Ragan  <gzr@eazel.com>

	* libnautilus-extensions/nautilus-undoable.c
	* libnautilus-extensions/nautilus-undoable.h
	* libnautilus-extensions/nautilus-undo-manager.c
	* libnautilus-extensions/nautilus-undo-manager.h
	* libnautilus-extensions/nautilus-undo-transaction.c
	* libnautilus-extensions/nautilus-undo-transaction.h
	* libnautilus-extensions/nautilus-undo-manager-private.h
	Added architecture for undo mechanism.
	NautilusUndoManager maintains undo and redo queues of NautilusUndoTransactions
	as well as maintaining various state information pertinant to the user interface.
	NautilusUndoTransaction contains a transaction name and a list of NautilusUndoables.
	NautilusUndoable is a object that contains a pointer to an object and a GData object.
	The GData object contains named data that can be added and retrieved during an undo/
	redo operation.  The NautilusUndoable also emits signals to the object that enables it
	to perform the undo and redo operations.  I will write up more complete documents when the
	code has matured.

	* libnautilus-extensions/nautilus-icon-container.c
	* libnautilus-extensions/nautilus-icon-container.h
	* src/file-manager/fm-icon-view.c
	Removed obsolete undo functions and callbacks.  These were invalidated
	by the new undo mechanism.

	* src/ntl-main.c
	Added call to nautilus_undo_manager_initialize_global_manager() in main.
	This call initializes a Nautilus global undo manager.
	Also fixed some minor coding style issues.

	* nautilus-window-menus.c
	edit_menu_undo_callback():
	Added callback to handle selection of Undo item form edit menu.  Callback
	checks with Undo Manager for a current undo transaction and asks manager to
	perform an undo if there is one.