* Due to the shutdown issues the TestConductorTransport is by
default not active, but it's easy to activate it and exception
will be thrown if trying to use the featues that require it, i.e
blackhole, passThrow and throttle
* Documented
* Major refactoring to remove the need to use special
Cluster instance for testing. Use default Cluster
extension instead. Most of it is trivial changes.
* Used failure-detector.implementation-class from config
to swap to Puppet
* Removed FailureDetectorStrategy, since it doesn't add any value
* Added Cluster.joinSeedNodes to be able to test seedNodes when Addresses
are unknown before startup time.
* Removed ClusterEnvironment that was passed around among the actors,
instead they use the ordinary Cluster extension.
* Overall much cleaner design
* Gossip is not exposed in user api
* Better and more events
* Snapshot event sent to new subscriber
* Updated tests
* Periodic publish only for internal stats
