* Failure detector was previously copied with refactoring to
akka-remote and this refactoring makes use of that and removes
the failure detector in akka-cluster
* Adjustments to reference.conf
* Refactoring of FailureDetectorPuppet
* When a def starts with if and is not a oneliner the if
should be on a new line.
* The reason is that it might be easy to miss the if when
reading the code.
* Subscribe to InstantMemberEvent and start heartbeating when
InstantMemberUp. Same for metrics.
* HeartbeatNodeRing data structure for bidirectional mapping of
heartbeat sender and receiver. Not using ConsistentHash anymore.
Node addresses are hashed to ensure that neighbors are spread out.
* HeartbeatRequest when receiver detects that it has not received
expected heartbeats.
* New test InitialHeartbeatSpec that simulates the problem
* Add/remove some related conf properties
* Add some more logging to be able to diagnose eventual problems
* Explicit config of nr-of-end-heartbeats
* akka.cluster.StressSpec
* Configurable number of nodes and duration for each step
* Report metrics and phi periodically to see progress
* Configurable payload size
* Test of various join and remove scenarios
* Test of watch
* Exercise supervision
* Report cluster stats
* Test with many actors in tree structure
Apart from the test this commit also solves some issues:
* Avoid adding back members when downed in ClusterHeartbeatSender
* Avoid duplicate close of ClusterReadView
* Add back the publish of AddressTerminated when MemberDowned/Removed
it was lost in merge of "publish on convergence", see #2779
