YARN-1669. Modified RM HA handling of protocol level service-ACLS to be available across RM failover by making using of a remote configuration-provider. Contributed by Xuan Gong.
svn merge --ignore-ancestry -c 1564549 ../../trunk/
Ran into minor import related conflicts that I merged manually.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1564552 13f79535-47bb-0310-9956-ffa450edef68