YARN-1684. Fixed history server heap size in yarn script. Contributed by Billie Rinaldi.
svn merge --ignore-ancestry -c 1564193 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1564195 13f79535-47bb-0310-9956-ffa450edef68