Adds server button and IP text field to GameMenu

Adds server button, IP text field and greys out all components of
GameMenu except Single Player button since it is the only one that is
currently functioning.
Gives functionality to Direct IP and Server

The direct IP button starts a client and connects to the address
specified in the IP address text field. The server button starts a
server in the background listening on port 1729.
Model now can send packets to two addresses