Merge r1601980 from trunk. YARN-2125. Changed ProportionalCapacityPreemptionPolicy to log CSV in debug level. Contributed by Wangda Tan

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1601981 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-10656. Merging change r1601985 from trunk

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1601986 13f79535-47bb-0310-9956-ffa450edef68