ZooKeeper based Revision Manager should use Recoverable Zookeeper

The current ZooKeeper implementation doesn't handle errors properly (from ZK). It would be good to move away from using ZK directly and use a client that makes it simpler to work with ZK.

HBase has one built in that we could use: https://github.com/apache/hbase/blob/trunk/src/main/java/org/apache/hadoop/hbase/zookeeper/RecoverableZooKeeper.java