integrated AddressTerminatedTopic into EndpointManager and ActorCell per #314
fixed the failing unit test in #314

Still have some extra work needed in order to complete the unit test as
specified in the canonical Akka.Remote RemoteWatcherSpec.
close #314
added cleanup for after shutdown
implemented AddressTerminated hooks inside RemoteDaemon
Merge pull request #318 from Aaronontheweb/remote-watcher

Remote watcher test fixed and finished - resolves #314