HADOOP-9935. Revert from trunk.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1523839 13f79535-47bb-0310-9956-ffa450edef68
YARN-1001. Added a web-service to get statistics about per application-type per state for consumption by downstream projects. Contributed by Zhijie Shen.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1523855 13f79535-47bb-0310-9956-ffa450edef68
YARN-1184. ClassCastException during preemption enforcement.



git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1523863 13f79535-47bb-0310-9956-ffa450edef68
HDFS-5207. In BlockPlacementPolicy.chooseTarget(..), change the writer and the excludedNodes parameter types respectively to Node and Set.  Contributed by Junping Du


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1523875 13f79535-47bb-0310-9956-ffa450edef68
Merge r1523804 through r1523877 from trunk.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/HDFS-2832@1523878 13f79535-47bb-0310-9956-ffa450edef68