YARN-1611. Introduced the concept of a configuration provider which can be used by ResourceManager to read configuration locally or from remote systems so as to help RM failover. Contributed by Xuan Gong.
svn merge -c 1564002 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1564003 13f79535-47bb-0310-9956-ffa450edef68
YARN-1639. Modified RM HA configuration handling to have a way of not requiring separate configuration files for each RM. Contributed by Xuan Gong.
svn merge --ignore-ancestry -c 1564032 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1564033 13f79535-47bb-0310-9956-ffa450edef68
YARN-1659. Defined the ApplicationTimelineStore store as an abstraction for implementing different storage impls for storing timeline information. Contributed by Billie Rinaldi.
svn merge --ignore-ancestry -c 1564037 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1564038 13f79535-47bb-0310-9956-ffa450edef68
YARN-1668. Modified RM HA handling of admin-acls to be available across RM failover by making using of a remote configuration-provider. Contributed by Xuan Gong.
svn merge --ignore-ancestry -c 1564043 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1564044 13f79535-47bb-0310-9956-ffa450edef68