Edit on the publishing a release and added section on how to do a snapshot

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1521311 13f79535-47bb-0310-9956-ffa450edef68
HBASE-9476 Yet more master log cleanup

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1521315 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/trunk' into trunk-gd