HDFS-7555. Remove the support of unmanaged connectors in HttpServer2. Contributed by Haohui Mai.
HADOOP-11429. Findbugs warnings in hadoop extras. Contributed by Varun Saxena.
HDFS-7557. Fix spacing for a few keys in DFSConfigKeys.java (Colin P. McCabe)
HADOOP-11414. FileBasedIPList#readLines() can leak file descriptors. (ozawa)

(cherry picked from commit ecf1469fa51f9977f70652fac313d4a9ec1eb86f)
Merge remote-tracking branch 'remotes/origin/branch-2' into branch-2