updated game start and end

I've updated the game with faster and better map generation, along with a feature that lets you pick a new map as many times as you like before you start the game.

Also, we now detect when a player is eliminated and skip them in the rotation; and when all but one player is eliminated, declare game over! No fireworks yet.  But it's getting there!

I will do a few more finishing touches before I call this "done," but it's very close.  Enjoy!