testing: add close-without-shutdown.hs
testing: add close-without-shutdown.hs

Properties:

 * send followed by recv works

 * recv returns an empty string, and keeps returning empty strings,
   when the remote host closes the connection.

   However, it fails with WSAECONNRESET if the other side closed the
   connection without reading outstanding data sent to it.
   See http://stackoverflow.com/q/2974021/149391

   Apparently, this is what 'shutdown' is for.

joeyadams/haskell-iocp