HDFS-6752: Merging r1613487 from branch-2 to branch-2.5.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2.5@1613492 13f79535-47bb-0310-9956-ffa450edef68
Fix up HDFS CHANGES.txt for 2.5.0

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2.5@1613497 13f79535-47bb-0310-9956-ffa450edef68
Fix up Common CHANGES.txt for 2.5.0

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2.5@1613500 13f79535-47bb-0310-9956-ffa450edef68