Patch to avoid 'Connection reset by peer' error for rsync on cygwin

[Martin Pool]

On 25 Apr 2002, Dave Dykstra <dwd at bell-labs.com> wrote:
> > The problem is caused because rsync does not close its sockets, and WinSock is a
> > quite strict on this. The solution is to shutdown and close the fd.
> > This is a 5-minute hack I've done to fix the obvious occurrences of the problem.
> > It might be better to extend rsyncs cleanup functions for this, but here it is
> > anyway to alert people to the problem and its fix.

> Does anybody know if this might cause problems on non-Windows machines?
> Would "shutdown" need to be checked in configure, or is it implemented on
> all Unix variants?  I don't recall ever seeing a need for it on Unix.