CHANGES for HDFS-347 branch.
These will be integrated to trunk CHANGES.txt after merge


HDFS-4353. Encapsulate connections to peers in Peer and PeerServer classes.
(Colin Patrick McCabe via todd)

HDFS-4354. Create DomainSocket and DomainPeer and associated unit tests.
(Colin Patrick McCabe via todd)

HDFS-4356. BlockReaderLocal should use passed file descriptors rather than paths.
(Colin Patrick McCabe via todd)