HDFS-6455. Merging change r1612947 from trunk

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1612949 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-10887. Add XAttrs to ViewFs and make XAttrs + ViewFileSystem internal dir behavior consistent. Contributed by Stephen Chu.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1612953 13f79535-47bb-0310-9956-ffa450edef68
svn merge -c 1612950 FIXES: YARN-2147. client lacks delegation token exception details when application submit fails. Contributed by Chen He


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1612955 13f79535-47bb-0310-9956-ffa450edef68