HDFS-5394: Fix race conditions in DN caching and uncaching (cmccabe)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1539909 13f79535-47bb-0310-9956-ffa450edef68
HDFS-5476. Snapshot: clean the blocks/files/directories under a renamed file/directory while deletion. Contributed by Jing Zhao.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1540142 13f79535-47bb-0310-9956-ffa450edef68
HDFS-5371. Let client retry the same NN when dfs.client.test.drop.namenode.response.number is enabled. Contributed by Jing Zhao.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1540197 13f79535-47bb-0310-9956-ffa450edef68
YARN-1121. Changed ResourceManager's state-store to drain all events on shut-down. Contributed by Jian He.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1540232 13f79535-47bb-0310-9956-ffa450edef68
HDFS-5325. Remove WebHdfsFileSystem#ConnRunner. Contributed by Haohui Mai.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1540235 13f79535-47bb-0310-9956-ffa450edef68
merge of r1535792 through r1540238 from trunk.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/HDFS-2832@1540239 13f79535-47bb-0310-9956-ffa450edef68