Specialization of Akka.Remote.RemoteWatcher that keeps track of cluster member nodes and is responsible for watchees on cluster nodes. Akka.Actor.AddressTerminated is published when a node is removed from cluster `RemoteWatcher` handles non-cluster nodes. `ClusterRemoteWatcher` will take over responsibility from `RemoteWatcher` if a watch is added before a node is member of the cluster and then later becomes cluster member.