YARN-1660. Simplified the RM HA configuration to accept and be able to simply depend just on
configuration properties of the form yarn.resourcemanager.hostname.RMID and use the default
ports for all service addresses. Contributed by Xuan Gong.
svn merge --ignore-ancestry -c 1565523 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1565524 13f79535-47bb-0310-9956-ffa450edef68