HBASE-8531 TestZooKeeper fails in trunk/0.95 builds

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.95@1482891 13f79535-47bb-0310-9956-ffa450edef68
HBASE-8535 Test for zk leak does not account for unsynchronized access to zk watcher

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.95@1482904 13f79535-47bb-0310-9956-ffa450edef68