[x] Games should be saved to disk on server exit if there are any active ones.
[x] Game IDs should be loaded by the server when started. These are the hibernated games.
[x] When joining a game, check if there is a hibernated game with the given ID, if so, it should load it from disk.
[x] When a game is created (or being saved to disk), we should check for any games that do not have any of the players connected, then delete the game.
Game cleanup should allow the following: