HDFS-6632. Reintroduce dfs.http.port / dfs.https.port in branch-2. Contributed by Yongjun Zhang.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1611794 13f79535-47bb-0310-9956-ffa450edef68
Move CHANGES.txt info for HDFS-6632 from 2.6 to 2.5 section.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1611808 13f79535-47bb-0310-9956-ffa450edef68