[PATCH v4] emacs: logically group def{custom,face}s

[Austin Clements]

LGTM.

Quoth Pieter Praet on Jan 16 at 11:38 am:
> - Add `notmuch-send' to the `message' group, as per Austin's
>   recommendation [1].

This is actually the reverse of what I was suggesting (though is also
reasonable).  Since notmuch uses message-mode, I was saying that the
notmuch group (or the notmuch-send group) should link to the message
group.  That way, if you customize-group notmuch, you get all of the
options that affect notmuch, even those that aren't strictly notmuch
variables.