HDFS-6578. add toString method to DatanodeStorage for easier debugging. (Contributed by Yongjun Zhang)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1604942 13f79535-47bb-0310-9956-ffa450edef68
YARN-2191. Added a new test to ensure NM will clean up completed applications in the case of RM restart. Contributed by Wangda Tan

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1604949 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-10659. Refactor AccessControlList to reuse utility functions and to improve performance. (Contributed by Benoy Antony)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1604955 13f79535-47bb-0310-9956-ffa450edef68