HBASE-8211 Support for NN HA for 0.94 (Himanshu)

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.94@1464785 13f79535-47bb-0310-9956-ffa450edef68
HBASE-8169 TestMasterFailover#testMasterFailoverWithMockedRITOnDeadRS may fail due to regions randomly assigned to a RS (Jeffrey Zhong)

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.94@1464787 13f79535-47bb-0310-9956-ffa450edef68
HBASE-8092 bulk assignment in 0.94 doesn't handle ZK errors very well

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.94@1464804 13f79535-47bb-0310-9956-ffa450edef68