pass cluster-state to INimbus

This pull gives me access to cluster-state in INimbus, which is needed for this pull https://github.com/nathanmarz/storm-mesos/issues/5

"IMPORTANT: CuratorFramework instances are fully thread-safe. You should share one CuratorFramework per ZooKeeper cluster in your application." https://github.com/Netflix/curator/wiki/Framework

MesosNimbus needed zk style state, so this pull gets it done. Without making a 2nd curator framework.

I had to use Object for clusterState because ClusterState is a protocol, and therefore not accessible due to compilation ordering where javac goes first in storm source code.  The clojure compiler does generate a class byte code for ClusterState but that comes after javac is finished. So other projects which depend on storm can merely cast the argument clusterState to ClusterState.