Make cluster fault handling more robust, see #3030

* ClusterCoreDaemon and ClusterDomainEventPublisher can't be restarted
  because the state would be obsolete.
* Add extra supervisor level for ClusterCoreDaemon and
  ClusterDomainEventPublisher, which will shutdown the member
  on failure in children.
* Publish the final removed state on postStop in
  ClusterDomainEventPublisher. This also simplifies the removing
  process.