Added game as a static member of MainViewController

This allows it to be accessible from elsewhere.  Double clicking a game sets it as the active game.

Also added a few bugfixes that did not get merged into this version:
  - actually store moderator when a new game is created
  - filter New tab of games to only show those you are the moderator for.

Committed by: ajthompson, austintrose, friscis, benkorza