HBASE-8219 Align Offline Merge with Online Merge

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1465943 13f79535-47bb-0310-9956-ffa450edef68
set maven mem to 3.1G in test-patch.properties

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1465964 13f79535-47bb-0310-9956-ffa450edef68