HDFS-6163. Fix a minor bug in the HA upgrade document. Contributed by Fengdong Yu.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1582421 13f79535-47bb-0310-9956-ffa450edef68
HDFS-5978. Create a tool to take fsimage and expose read-only WebHDFS API. Contributed by Akira Ajisaka.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1582433 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-10442. Group look-up can cause segmentation fault when certain JNI-based mapping module is used. (Kihwal Lee via jeagles)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1582451 13f79535-47bb-0310-9956-ffa450edef68