HDFS-4356. BlockReaderLocal should use passed file descriptors rather than paths. Contributed by Colin Patrick McCabe.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/HDFS-347@1432335 13f79535-47bb-0310-9956-ffa450edef68
HDFS-4388. DomainSocket should throw AsynchronousCloseException when appropriate. Contributed by Colin Patrick McCabe.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/HDFS-347@1432339 13f79535-47bb-0310-9956-ffa450edef68
HDFS-4390. Bypass UNIX domain socket unit tests when they cannot be run. Contributed by Colin Patrick McCabe.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/HDFS-347@1432350 13f79535-47bb-0310-9956-ffa450edef68