YARN-1512. Enhanced CapacityScheduler to be able to decouple scheduling from node-heartbeats. Contributed by Arun C Murthy.
svn merge --ignore-ancestry -c 1578722 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2.4@1578725 13f79535-47bb-0310-9956-ffa450edef68