svn merge -c 1514768 FIXES: Update CHANGES.txt to reflect merge of MR-1981 to branch-2.1-beta


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1514769 13f79535-47bb-0310-9956-ffa450edef68
HDFS-5102. Merge change r1514797 from trunk.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1514802 13f79535-47bb-0310-9956-ffa450edef68
HDFS-5105. Merging change r1514852 from trunk to branch-2.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1514872 13f79535-47bb-0310-9956-ffa450edef68