YARN-1730. Implemented simple write-locking in the LevelDB based timeline-store. Contributed by Billie Rinaldi.
svn merge --ignore-ancestry -c 1574145 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1574146 13f79535-47bb-0310-9956-ffa450edef68
HDFS-6053. Fix TestDecommissioningStatus and TestDecommission in branch-2. Contributed by Jing Zhao.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1574178 13f79535-47bb-0310-9956-ffa450edef68
YARN-986. Changed client side to be able to figure out the right RM Delegation token for the right ResourceManager when HA is enabled. Contributed by Karthik Kambatla.
svn merge --ignore-ancestry -c 1574190 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1574191 13f79535-47bb-0310-9956-ffa450edef68
HDFS-6047 TestPread NPE inside in DFSInputStream hedgedFetchBlockByteRange (stack)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1574206 13f79535-47bb-0310-9956-ffa450edef68