Multiplayer!

I've added full two-player support with a dedicated player based inventory system to this prototype, after getting some feedback on how it'd be cool to play with a friend.

Since the initial publishing of this draft, these things are also new

• the Upgrade Mode now displays piece descriptions
• missing king-in-check piece coverage was added - now all pieces actually run the necessary checks!
• quiescence search was capped at a depth of 8 due to a memory overflow issue (plus now it's just a lot snappier!)
• fixed highlighting bug in Board Extension mode
• move ordering was improved

That's all! Happy Chessing