Merge r1504261 from trunk to branch-2 for YARN-922. Change FileSystemRMStateStore to use directories (Jian He via bikas)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1504264 13f79535-47bb-0310-9956-ffa450edef68
Merge r1504288 from trunk to branch-2 for YARN-865. RM webservices can't query based on application Types. Contributed by Xuan Gong.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1504290 13f79535-47bb-0310-9956-ffa450edef68
HDFS-5005. Merging r1504326 from trunk.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1504327 13f79535-47bb-0310-9956-ffa450edef68