HDFS-5024. Make DatanodeProtocol#commitBlockSynchronization idempotent. Contributed by Arpit Agarwal.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1506789 13f79535-47bb-0310-9956-ffa450edef68
YARN-688. Fixed NodeManager to properly cleanup containers when it is shut down. Contributed by Jian He.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1506814 13f79535-47bb-0310-9956-ffa450edef68