YARN-1976. Fix CHANGES.txt for YARN-1976.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1594123 13f79535-47bb-0310-9956-ffa450edef68
HDFS-6367. EnumSetParam$Domain#parse fails for parameter containing more than one enum. Contributed by Yi Liu.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1594150 13f79535-47bb-0310-9956-ffa450edef68
Merge branch 'trunk' into HDFS-6326
HDFS-6326: code review feedback