windows StreamPeerWinsock::set_nodelay implementation

StreamPeerWinsock::set_nodelay was a no-op.  Copied the code from the
POSIX implementation because it is also correct on Windows per
http://msdn.microsoft.com/en-us/library/windows/desktop/ms740476%28v=vs.85%29.aspx.
Merge pull request #107 from bscranton/master

Windows StreamPeerWinsock::set_nodelay implementation