Fix hadoop-yarn-project/CHANGES.txt for YARN-759

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1493843 13f79535-47bb-0310-9956-ffa450edef68
HDFS-4875. Merging change r1493850 from trunk.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1493854 13f79535-47bb-0310-9956-ffa450edef68
YARN-822. Renamed ApplicationToken to be AMRMToken, and similarly the corresponding TokenSelector and SecretManager. Contributed by Omkar Vinit Joshi.
svn merge --ignore-ancestry -c 1493889 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1493890 13f79535-47bb-0310-9956-ffa450edef68