cli: add --include-html option to notmuch show

[John Lenz]

On Sun Jul 21 15:23 -0500 2013, Tomi Ollila <tomi.ollila at iki.fi> wrote:
> On Tue, Jul 02 2013, John Lenz <lenz at math.uic.edu> wrote:
> 
> > For my client, the largest bottleneck for displaying large threads is
> > exporting each html part individually since by default notmuch will not
> > show the json parts.  For large threads there can be quite a few parts and
> > each must be exported and decoded one by one.  Also, I then have to deal
> > with all the crazy charsets which I can do through a library but is a
> > pain.
> 
> This looks like a useful option. I just wonder what effect does different
> charsets do to the output (is text/html content output verbatim (with just
> json/sexp escaping of '"' -characters). 
> 
> If you added test(s) showing what happens with different charsets
> (like one message having 3 text/html parts, one us-ascii, one iso-8859-1
> and one utf-8) that would make things clearer and (also) protect us from 
> regressions.
> 

Ok, I'll add some tests, but everything is converted to UTF-8 by gmime.  If
you look, I didn't add any extra code actually.  Instead I just changed
the if branch taken depending on the option and the content type.  The existing
code already converted everything to UTF-8.