Merge 1524829 from trunk to branch-2 for YARN-353. Add Zookeeper-based store implementation for RMStateStore. Contributed by Bikas Saha, Jian He and Karthik Kambatla.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1524831 13f79535-47bb-0310-9956-ffa450edef68
MAPREDUCE-5504. mapred queue -info inconsistent with types (Kousuke Saruta via tgraves)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1524843 13f79535-47bb-0310-9956-ffa450edef68
MAPREDUCE-5488. Changed MR client to keep trying to reach the application when it sees that on attempt's AM is down. Contributed by Jian He.
svn merge --ignore-ancestry -c 1524856 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1524857 13f79535-47bb-0310-9956-ffa450edef68