HBASE-9099: logReplay could trigger double region assignment

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1510615 13f79535-47bb-0310-9956-ffa450edef68
HBASE-7980 TestZKInterProcessReadWriteLock fails occasionally in QA test run

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1510753 13f79535-47bb-0310-9956-ffa450edef68
HBASE-9095. AssignmentManager's handleRegion should respect the single threaded nature of the processing

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1510799 13f79535-47bb-0310-9956-ffa450edef68