Work in progress - still to do:
- renames appear as 'Update Deck' - easiest way to solve it would
be to have a separate backend method for renames
- drag&drop of decks not yet undoable
- since the undo status is updated after the backend method ends,
the older checkpoint() calls need to be replaced with an
update_undo_status() at the end of the call - if we just remove the
checkpoint, then the menu doesn't get updated
