YARN-2300. Improved the documentation of the sample requests for RM REST API - submitting an app. Contributed by Varun Vasudev.
svn merge --ignore-ancestry -c 1612981 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1612982 13f79535-47bb-0310-9956-ffa450edef68