+con #3677 Limit delta in DistributedPubSubMediator
!con #3679 Make protobuf serialization for DistributedPubSubMediator
=clu #3683 Don't trigger extra heartbeat when not expected sender
=doc #3684 Document that SslTlsSupport doesn't support Tcp.WriteCommand.
Merge pull request #1809 from akka/wip-3684-ssltlssupport-do-not-support-tcp-writecommands-ban

(forward port) =doc #3684 Document that SslTlsSupport doesn't support Tcp.WriteCommand.
Merge pull request #1792 from akka/wip-3677-limit-delta-patriknw

+con #3677 Limit delta in DistributedPubSubMediator
Merge pull request #1812 from akka/wip-3679-protobuf-pubsub-patriknw

!con #3679 Make protobuf serialization for DistributedPubSubMediator
Merge pull request #1799 from akka/wip-3683-extra-heartbeat-patriknw

=clu #3683 Don't trigger extra heartbeat when not expected sender
=doc Fix spelling. Change depreceated to deprecated
Merge pull request #1811 from benmccann/depreceated-spelling

=doc Fix spelling. Change depreceated to derecated
Merge remote-tracking branch: upstream/master