HDFS-6559: Merging r1603638 from trunk to branch-2.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1603639 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-10711. Cleanup some extra dependencies from hadoop-auth. (rkanter via tucu)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1603645 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-10716. Merging change r1603668 from trunk to branch-2.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1603672 13f79535-47bb-0310-9956-ffa450edef68
MAPREDUCE-5896. InputSplits should indicate which locations have the block cached in memory. (Sandy Ryza via kasha)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1603673 13f79535-47bb-0310-9956-ffa450edef68
HDFS-6553. Merging change r1603677 from trunk

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1603679 13f79535-47bb-0310-9956-ffa450edef68