YARN-1765. Added test cases to verify that killApplication API works across ResourceManager failover. Contributed by Xuan Gong.
svn merge --ignore-ancestry -c 1573735 ../../trunk/
svn merge --ignore-ancestry -c 1573736 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2.4@1573738 13f79535-47bb-0310-9956-ffa450edef68