Add note on recommended zk version

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1480421 13f79535-47bb-0310-9956-ffa450edef68
HBASE-7897 Add support for tags to Cell Interface

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1480430 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/trunk' into trunk-gd