HADOOP-9247. Merge r1438698 from trunk

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HADOOP-9255. relnotes.py missing last jira (tgraves)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.23@1439604 13f79535-47bb-0310-9956-ffa450edef68
merge -r 1439652:1439653 Merging YARN-133 to branch-0.23

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.23@1439656 13f79535-47bb-0310-9956-ffa450edef68