+clu #3627 Cluster router group  with multiple paths per node

* Use the ordinary routees.paths config property instead of
  cluster.routees-path
* Backwards compatible in deprecation phase
+act #3663 Package BalancingDispatcher for usage in router pool

* In fact, make it easy to define any dedicated dispatcher for a pool
+con #3669 Possibility to define routing logic in DistributedPubSub

* Serialization check in contrib
Merge pull request #1772 from akka/wip-3627-cluster-routee-paths-patriknw

+clu #3627 Cluster router group  with multiple paths per node
Merge pull request #1776 from akka/wip-3663-balancing-disp-patriknw

+act #3663 Package BalancingDispatcher for usage in router pool
Merge pull request #1778 from akka/wip-3669-routing-in-pubsub-patriknw

+con #3669 Possibility to define routing logic in DistributedPubSub
=act #3672 fix garbling of big outgoing Tcp.Write caused by mixup of buffers
!clu #3657 Lazy deserialization and TTL of Gossip message payload
Merge pull request #1782 from jrudolph/i/3672/fix-big-Writes

=act #3672 fix garbling of big outgoing Tcp.Write caused by mixup of buffers
Possibility to skip mima check in release
Merge pull request #1788 from akka/wip-no_mima-flag-in-release-patriknw

Possibility to skip mima check in release
+clu #3458 Adjust biased gossip for large cluster
Merge pull request #1786 from akka/wip-3657-lazy-deserial-patriknw

!clu #3657 Lazy deserialization and TTL of Gossip message payload
Merge pull request #1785 from akka/wip-3458-adjust-biased-gossip-patriknw

+clu #3458 Adjust biased gossip for large cluster
=doc Fix misspelled method reference in FSM
=clu #3676 Cache the last system name and protocol during deserialization.
Merge pull request #1781 from levinotik/documentation-fixes

=doc Fix misspelled method reference in FSM
=act #3680 fix SuspendReading being overruled by racy ChannelReadable
Merge pull request #1790 from akka/wip-3676-cache-the-last-system-and-protocol-ban

=clu #3676 Cache the last system name and protocol during deserialization.
Merge pull request #1793 from jrudolph/i/3680/fix-SuspendReading-race

=act #3680 fix SuspendReading being overruled by racy ChannelReadable