YARN-1787. Fixed help messages for applicationattempt and container sub-commands in bin/yarn. Contributed by Zhijie Shen.
svn merge --ignore-ancestry -c 1575482 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1575483 13f79535-47bb-0310-9956-ffa450edef68