!act #16125 Timeout Calls through CircuitBreaker.

CircuitBreaker used to wait idenfinitly for a call and only compare
duration after the facts. It will now throw a TimeoutException.

Ups. I cargo culted from here: 
https://github.com/akka/akka/blob/master/akka-actor/src/main/scala/akka/pattern/FutureTimeoutSupport.scala#L19