HDFS-5106. Merging change r1514911 from trunk to branch-2.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1514914 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-9880. Merge change r1514913 from trunk.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1514915 13f79535-47bb-0310-9956-ffa450edef68
YARN-107. Fixed ResourceManager and clients to better handle forceKillApplication on non-running and finished applications. Contributed by Xuan Gong.
svn merge --ignore-ancestry -c 1514918 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1514919 13f79535-47bb-0310-9956-ffa450edef68