YARN-321. Merging YARN-321 branch to trunk.
svn merge ../branches/YARN-321


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1561452 13f79535-47bb-0310-9956-ffa450edef68
YARN-1625. Fixed RAT warnings after YARN-321 merge. Contributed by Shinichi Yamashita.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1561458 13f79535-47bb-0310-9956-ffa450edef68
YARN-1613. Fixed the typo with the configuration name YARN_HISTORY_SERVICE_ENABLED. Contributed by Akira Ajisaka.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1561461 13f79535-47bb-0310-9956-ffa450edef68