HADOOP-9418.  Add symlink support to DistributedFileSystem (Andrew Wang via Colin Patrick McCabe)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1502373 13f79535-47bb-0310-9956-ffa450edef68
YARN-333. Schedulers cannot control the queue-name of an application. (sandyr via tucu)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1502374 13f79535-47bb-0310-9956-ffa450edef68
HDFS-4978. Make disallowSnapshot idempotent. Contributed by Jing Zhao.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1502400 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/trunk' into trunk-gd
Merge remote branch 'origin/trunk-gd' into fb-HADOOP-9281-trunk-gd