create copy of GameAI instead of Game
While this is less efficient, it will compile. We need to be running
GameAI::notConnectableNodes on the game instance or from it access the
temporary game, which we cannot do because we can't access Game::nodes
from GameAI except through the inherited copy. Thus, for a fix, we copy
GameAI and call notConnectableNodes on it. The one alternative I thought
of was either using a friend function/class or making nodes public, both
of which don't seem like that great of ideas. If you have any ideas for
how to fix this...