HBASE-7403 Online Merge (Chunhui shen)

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1460306 13f79535-47bb-0310-9956-ffa450edef68
HBASE-8189 Shell commands of online region merge

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1460308 13f79535-47bb-0310-9956-ffa450edef68