Merge r1504264 from branch-2 to branch-2.1-beta for YARN-922. Change FileSystemRMStateStore to use directories (Jian He via bikas)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2.1-beta@1504270 13f79535-47bb-0310-9956-ffa450edef68
Merge r1503965 from branch-2 to branch-2.1-beta for YARN-927. Change ContainerRequest to not have more than 1 container count and remove StoreContainerRequest (bikas)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2.1-beta@1504277 13f79535-47bb-0310-9956-ffa450edef68