HDFS-5343. When cat command is issued on snapshot files, getting unexpected result. Contributed by Sathish.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1561325 13f79535-47bb-0310-9956-ffa450edef68
HDFS-5138. Support HDFS upgrade in HA. Contributed by Aaron T. Myers.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1561381 13f79535-47bb-0310-9956-ffa450edef68