Amending MR CHANGES.txt to reflect that MAPREDUCE-4049/4809/4807/4808 are in branch-2

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1438799 13f79535-47bb-0310-9956-ffa450edef68
HDFS-4443. Remove a trailing '`' character from the HTML code generated by NamenodeJspHelper.generateNodeData(..).  Contributed by Christian Rohling


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1438808 13f79535-47bb-0310-9956-ffa450edef68
Fix the bugs and the error in the test cases.
Merge remote-tracking branch 'apache/trunk' into MAPREDUCE-4956