Clean-up World/Game Instantiation about spacebattlearena

[hawkerm]

Think this is more likely to occur in an overpopulated 'small' world, so that's probably why I hadn't seen it until I was doing some random testing.

[hawkerm]

Should remove the 'pys' flag from GameWorld and have a 'start' method to initiate the gameloop, then have the game call that after initialization, so if there's an error it can throw an exception and not have a dangling thread (e.g. error with missing config section name).

This propagates up to ConfiguredWorld and the objlistener registration as well.

Game should just call start at the very beginning, this should avoid the whole issue with resetting the world too I believe.

[hawkerm]

I've reworked the initialization of the world within the game now that I have the Spawn Manager #83 take care of the creation of game objects. Believe this should be a non-issue now as the gameloop thread is only started after the world object has been initialized within the game.