HBASE-3787 Increment is non-idempotent but client retries RPC

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1542168 13f79535-47bb-0310-9956-ffa450edef68
HBASE-3787 Increment is non-idempotent but client retries RPC ADDENDUM add licence

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1542169 13f79535-47bb-0310-9956-ffa450edef68