emacs: tag: add customize for deleted/added tag formats
Add customize options for deleted/added tag formats. These are not
used yet but will be later in the series.
We switch to using `notmuch-apply-face' rather than `propertize' in
the defcustom for faces so that the faces for deleted/added tags add
to the default face attributes for the tag.
We special case deleting the unread tag as that tag is a strong visual
cue and we don't need that cue when we are just saying it used to be
unread. Thus, we revert to the normal tag face with strikethough for
deleted unread tags.
projects / notmuch / commit