HDFS-5382. Implement the UI of browsing filesystems in HTML 5 page. Contributed by Haohui Mai.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1534368 13f79535-47bb-0310-9956-ffa450edef68
HDFS-5347. Add HDFS NFS user guide. Contributed by Brandon Li

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1534377 13f79535-47bb-0310-9956-ffa450edef68