Multiplayer started

I started working on the multiplayer. To simplify the development process, I designed the multiplayer setup screen with regular Java UI elements instead of Open-IG graphics.

Game organizers will be able to set up all game parameters similar to a skirmish game. AI players may be added to the game as well, which can be in the same group as the human players.

Game organizers may allow the client users to select their own properties: race, icon, traits and groups.