HADOOP-10040. Merging change r1531978 from branch-2 to branch-2.2

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2.2@1531981 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-10040. Merging change r1531984 from branch-2 to branch-2.2

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2.2@1531985 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-10040. Merging change r1531996 from branch-2 to branch-2.2

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2.2@1531998 13f79535-47bb-0310-9956-ffa450edef68
MAPREDUCE-5546. Merging change r1532017 from branch-2 to branch-2.2

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2.2@1532019 13f79535-47bb-0310-9956-ffa450edef68