Return of the DefaultSystemMessageQueue fixes. See #3170
Merge pull request #1276 from akka/wip-3170-deadlock-in-calling-thread-dispatcher-ban

Return of the DefaultSystemMessageQueue fixes. #3170
Correctly serialize local actor refs from other actor systems. See #3137
Cleaning up the ActorRef serialization according to review. See #3137
Merge pull request #1272 from akka/wip-3137-seralize-actor-refs-from-other-systems-ban

Correctly serialize local actor refs from other actor systems #3137