[RFC PATCH 2/4] Add NOTMUCH_MESSAGE_FLAG_EXCLUDED flag

[Austin Clements]

This is looking really good.  I think this overall approach is
significantly better than the initial exclude support and the UI
aspects look like they should be much more pleasant.

Quoth Mark Walters on Jan 29 at  6:36 pm:
> 
> Ok I now have a patch set which might be complete enough to be worth
> reviewing. It is essentially complete and appears to work.
> 
> Things that still need doing: 
>        updating the test suite. The series changes notmuch-show to
>        output the exclude flag so several tests need updating. Of
>        course, the new functionality needs some tests too.
>        
>        emacs/notmuch.el I think it would be nice to hide (make
>        invisible) threads with no matching non-excluded messages (with a
>        toggle for visibility) but that is definitely beyond my elisp
>        skills.

I'm happy to do that once this goes in.

> The first patch of the series is not really part of the series: it adds
> a --do-not-exclude option to tell the command not to exclude. I think
> this is useful anyway, but it also simplifies behaviour decisions with
> the excludes. For example notmuch count will only count matching
> non-excluded messages but notmuch count --do-not-exclude will count 
> all matching messages excluded or not.
> 
> One outstanding issue is that raised in
> id:"20120124025331.GZ16740 at mit.edu". I will need to think about
> that. 
> 
> Best wishes
> 
> Mark
>