Metaclass trickery!

Trying to cleanly keep track of all the game objects.

This uses a couple (pretty simple) metaclasses to make it so it is easy to figure out what object types are in a given game.

The hope here is to make it so the base server code can handle actions that require knowing the type of objects in a game.
The alternative would be including some repetitive boiler plate code in the templates so that they can expliticy do these things. I'd prefer not to do that so the templates can be as minimalist as possible.

I'm not thrilled about this implementation, so if someone has a different way to do it, please share.