HBASE-10014 HRegion#doMiniBatchMutation rollbacks the memstore even if there is nothing to rollback.

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1544080 13f79535-47bb-0310-9956-ffa450edef68
HBASE-10013 Enhance the message about ZK when there is an exception

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1544104 13f79535-47bb-0310-9956-ffa450edef68