basic functionality - swap sides command

[NBKelly]

Just adding my WIP as I go. This is intended as part of a teaching mode/new player mode, so the more experienced player can demonstrate a concept or show stuff.

• Since the command needs to manipulate the lobby, it needs to happen outside of the commands interface (in game.clj). I'll update it later to make it 1) a dedicated button and 2) not a regular command
• It needs to have double-sided consent (like undo turn)
• Right now, the stats panels on the left (where credits/etc are) don't update when sides get swapped. This is similar to starting a private game after ending another private game, with sides opposite. Fixing that bug will fix this bug - we essentially need to find a way to make those panels actually scry the gamestate for your side instead of checking some cached side in a cached view of the lobby somewhere.
• You should be able to swap back without consent (or revoke consent)
• Things should get logged

Sooner or later I'll figure this all out.