DynamicCluster.replaceMember: throw StopFailedRuntimeException

- new exception type to indicate this failure, rather than having to
  rely on toString message of exception!
AutoScalerPolicy: use Duration instead of Long

- same for TimeWindowedList and SizeHistory
- deprecates methods that took Long for setting config
Deprecates MemberFailureDetectionPolicy

- preferring ServiceFailureDetector, which now has more functionality
  with the stabilisation delay support.
(Connection|Service)FailureDetector cleanup