Implement Saving

[ava-cassiopeia]

Implement the ability to save the game using the command $save.

Should have a limit to 3 saves per game, and will save all the saves in saves/[gamename]/.

[JiFish]

I've written something quick and dirty that serves my basic needs. The real challenge seems to be finding a tidy way of temporarily catching and processing the save/load messages from dfrotz.

Edit: Also, it would be good if it saved to an autosave file in the case of a graceful close. Possibly also on a timer.