Simplified SocketServerThread read loop.
Added in client-side parsing for leavegame message.

Some other small changes too.
Commenting, some small cleanup.
Implemented code for player exiting the game.

* Updating the server through the protocol in serverprotocol class.
* Reworked in-game scoreboard to support updates to players.
* Added leaveGame function in GameUi to do client-side work.

And it'll be tested tomorrow.. I'm tired.. and have work in the morning :(.