Merging r1510070 from trunk to branch-2 for YARN-994. HeartBeat thread in AMRMClientAsync does not handle runtime exception correctly (Xuan Gong via bikas)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1510071 13f79535-47bb-0310-9956-ffa450edef68