Chat Server example

Attached is a sample project that implements a text chat server written using the middle layer of the UNet HLAPI, that demonstrates the NetworkServerSimple class that is new in Unity 5.3.

The NetworkServerSimple class has no "game" functionality - unlike the existing NetworkServer class. It is a pure network server that handles messages, with no spawning, player management or singleton interface.

This project uses message classes derived from MessageBase, not [Command] and [ClientRpc] calls.

There is a simple user interface that can be used to test the system.