Merge r1529039 and r1529048 from trunk to branch-2 for YARN-1256. NM silently ignores non-existent service in StartContainerRequest (Xuan Gong via bikas)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1529049 13f79535-47bb-0310-9956-ffa450edef68