Turn akka.actor.debug.unhandled on.

Have unhandled messages converted into actual Debug messages.
Change GamePlugin to an actor.

GamePlugin receives a Handle message which contains a Request instance and
returns the result as a string. For now, there is only one instance of
GamePlugin and it is supervised by BeyondSupervisor.
Make actor accessible from Context.

BeyondContextFactory.makeContext is overriden to return an instance of
BeyondContext which provides an refrence to ActorRef.
Add timer functions to BeyondGlobal.

The following 4 timer functions are added to BeyondGlobal:
- setInterval
- clearInterval
- setTimeout
- clearTimeout