Should nmh be RFC 2822 compliant (bug report #3356)

Apparently the powers that be don't want informational messages to be part
of the 'In-Reply-To:" fields anymore (http://www.faqs.org/rfcs/rfc2822.html).

The obsolete fields could look like:

In-reply-to: Your message of "Fri, 27 Jun 2003 13:35:24 EDT."
             <200306271735(_dot_)h5RHZOmm001391(_at_)aoi-industries(_dot_)com> 

which is what nmh puts in by default.  Now only the information in the
angle brackets is to be supplied.

Should we change this?

Thanks.