==== Current limitations ====
- For HTML emails send in Text+HTML (aka multipart/alternative) we can display
  the HTML version only because it's the first attachment we treat.

==== For a future release ====
- Refactor DB:
-- Mime messages tables (esp. multipart/alternative)
-- Store often used headers as table columns (date, ctype, subject, message_id)
- Insert "Reply" form with Javascript to avoid page reload+move to anchor, which is a bit disturbing...
- provide way to post to mailing list in the main List page.
- extend search to message bodies (now only on subjects)
