Improved debugging

[tspivey]

Debugging should be improved.

• Players have no way to log that a duel broke, so I have to be there to figure out which one broke or manually go through the duels until I find one that doesn't end with 05 or 0B.
• There's no easy way to disable deck shuffling, so I can't create my own debug decks without editing the source code each time.
• The replay command needs two users logged in for an interactive duel. Setting that up each time is annoying.