=tes,act,doc Make dilated an extension method and deprecate TestKit.dilated in favor of JavaTestKit.dilated
=con #3880 Keep track of all shards per region in ClusterSharding

* The problem was that ShardRegion actor only kept track of one shard
  id per region actor.  Therefore the Terminated message only removes
  one of the shards from its registry when there are multiple shards
  per region.
* Added failing test and solved the problem by keeping track of all
  shards per region
* Also, rebalance must not be done before any regions have been
  registered
=con #3882 Defer watch in ClusterSharding until after recovery

* To avoid unnecessary and costly watch/unwatch to non-existing systems.
* This avoids the problematic scario revealed in ticket 3879
=clu #3871 Harden SurviveNetworkInstabilitySpec

* The problem was that the unreachability observed by second node
  was leaking from previous test step and when adding the blackhole,
  it could not heal and that caused the leader to not be able to remove
  the downed second node because some other nodes were still marked as
  unreachable.
* The first node was not included in the the awaitAllReachable check
  in the previous step, and the order of awaitAllReachable and
  awaitMembersUp was wrong.
* Included the awaitAllReachable check in assertCanTalk.
* Changed to two-way blackhole and using barrier instead of scheduled
  event to trigger the exceptions when the blackhole was in place
* We should investigate if unreachable observations from downed node
  can be excluded in the convergence check. Created separate ticket for
  that 3875.
=act - Make ConsistencySpec more consistent (has been prone to intermittent failures in the past
=rem #3879: Stop sysmsg redelivery for unknown systems after a timeout
Merge pull request #2021 from akka/wip-make-ConsistencySpec-more-consistent-√

=act - Make ConsistencySpec more consistent (has been prone to intermitt...
Merge pull request #2022 from drewhk/wip-3879-sysmsg-redelivery-bailout-drewhk

=rem #3879: Stop sysmsg redelivery for unknown systems after a timeout
Merge pull request #2012 from akka/wip-3871-SurviveNetworkInstabilitySpec-patriknw

=clu #3871 Harden SurviveNetworkInstabilitySpec
Merge pull request #2019 from akka/wip-3880-sharding-terminated-patriknw

=con #3880 Keep track of all shards per region in ClusterSharding
Merge pull request #2020 from akka/wip-3882-sharding-watch-after-recovery-patriknw

=con #3882 Defer watch in ClusterSharding until after recovery
Merge pull request #2015 from jozic/dilated

=tes,act,doc Make dilated an extension method and deprecate TestKit.dila...