HDFS-6156. Merge r1582847 from trunk.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1582849 13f79535-47bb-0310-9956-ffa450edef68
svn merge -c 1582851 from trunk for HADOOP-10449. Fix the javac warnings in the security package.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1582852 13f79535-47bb-0310-9956-ffa450edef68
svn merge -c 1582856 from trunk for HDFS-6168. Remove a deprecated constructor and the deprecated methods reportChecksumFailure, getDelegationToken(Text), renewDelegationToken and cancelDelegationToken from DistributedFileSystem.  


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1582857 13f79535-47bb-0310-9956-ffa450edef68
YARN-1883. TestRMAdminService fails due to inconsistent entries in UserGroups (Mit Desai via jeagles)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1582865 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-10450. Merging change r1582868 from trunk to branch-2.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1582871 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-10301. Merge r1582883 from trunk.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1582884 13f79535-47bb-0310-9956-ffa450edef68