YARN-599. Refactoring submitApplication in ClientRMService and RMAppManager to separate out various validation checks depending on whether they rely on RM configuration or not. Contributed by Zhijie Shen.
svn merge --ignore-ancestry -c 1477478 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1477479 13f79535-47bb-0310-9956-ffa450edef68
Move the CHANGES.txt entry for HDFS-4305 to the incompatible changes section.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1477489 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/branch-2' into branch-2-gd