Add ability to undo deleted dives by storing a list of the
deleted dives in a QUndoCommand.
Signed-off-by: Grace Karanja <gracie.karanja89@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Add the undocommands.cpp / undocommands.h files, which will hold a
collection of classes that will hold undo commands.
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>