Strip huge piles of cruft from the connection infrastructure. We now actually

Strip huge piles of cruft from the connection infrastructure.  We now actually
block inside accept rather than using select to poll and then calling accept
regardless of the outcome of the select call, and then failing because the
socket is non-blocking.

SocketClientConnection, SocketConnector, TCPClientConnection, TCPConnector,
connectTCP, UnixClientConnection, UnixConnector, connectUnix have gone.

loseConnection and stopListening and closeSocket (where they are needed) are
now called close.  startListening is now called listen.

Closes bug #379.

Relieves a weight from the shoulders of the universe.

Signed-off-by: Ewan Mellor <ewan@xensource.com>