HDFS-5077. NPE in FSNamesystem.commitBlockSynchronization().  Contributed by Plamen Jeliazkov.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1518852 13f79535-47bb-0310-9956-ffa450edef68
MAPREDUCE-5484. YarnChild unnecessarily loads job conf twice (Sandy Ryza)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1518858 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-9909. org.apache.hadoop.fs.Stat should permit other LANG. (Shinichi Yamashita via Andrew Wang)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1518863 13f79535-47bb-0310-9956-ffa450edef68
YARN-707. Added user information also in the YARN ClientToken so that AMs can implement authorization based on incoming users. Contributed by Jason Lowe.
svn merge --ignore-ancestry -c 1518868 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1518869 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-9774. Merging change r1518865 from trunk

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1518871 13f79535-47bb-0310-9956-ffa450edef68