Rounds ModLoader v1.2

A mod's entry point (the class which implements IMod) can now optionally implement IGui and/or INetworked for additional functionality.

The IGui interface will expose the OnGUI method, which mod-creators can use to leverage Unity's built-in IMGUI module for custom mod UI.

The INetworked interface exposes three methods:

- OnJoinRoom
    + Called whenever the player joins a networked room
- OnLeftRoom
    + Called whenever the player leaves a networked room
- OnHandShakeCompleted
    + Called when the user joins a room and the modloader has confirmed that both clients are running your mod