Added server functionality

Added server connection,
deleted redundant toString method in Move.java,
added terminal() in Main for while loop in main method,
added getMove and getPosition in Main that convert from the server's
notation to our Samuels' notation.
Right now the computer makes random legal moves (better than choosing
the first move like the client). We still need to implement minimax. To
run, simply enter our id and password when prompted.