Added hook for afew tagging for local mail.
Mail will now arrive tagged only as 'new' by notmuch.
afew will then tag the mail accordingly as inbox unread when it is
personal mail.
It will additionally filter out anything marked as spam, or e-mail
containing a List-Id header, which will be tagged as 'list' and not
arrive in the inbox. This filters out anything arriving from a mailing
list from the inbox.
Removed the archive tag -- anything not in the inbox, and not marked as
list is instead used as an automatic archive.
Mail sent by myself will be automatically tagged as 'sent' and also not
show up in the mailbox.
