configure --with-rsh=CMD and default blocking-IO support

[Martin Pool]

On 30 Jan 2002, Wayne Davison <wayned at users.sourceforge.net> wrote:
> A while back I argued for adding a --with-rsh=CMD option to configure
> and got some general agreement that it would be a good thing (especially
> for systems that don't have rsh at all).  However, the changes were
> never integrated into rsync.

OK, I agree --with-rsh should go in, but I think putting magic
characters into it is needlessly confusing.  I would feel much better
about a separate configure option to set the default O_NONBLOCK mode.

-- 
Martin