Added Networking Code

Added networking code that, when activated with the "-m" flag, will attempt to create a multiplayer game.
Initially, we search the LAN for any open games (anyone online with port 7776 open). If we manage to find someone with port 7776 open, we send them a PING (in this case, just the message "chess") and await their PONG (in this case "Play!"). Upon a successful ping/pong, we create the game and begin sending input back and forth, with some rudimentary turn mechanics.