Uwe Brauer wrote:
> Done, I sent it in three different formats:
>     -  gnus inline
>     -  seamonkey (thunderbird) html, inline
>     -  seamonkey (thunderbird) html, attachment

I've received those mails.  Thanks.  The revised code is attached.

I realized my fault was that the MIME parts that the code moves
to the top was only attachments.  In an example mail, but there
is an inline PDF part, that is not inlinable in Gnus normally[1].
So, I've changed the criteria so as to gather the ones that are
not inlinable in Gnus.

By the way, Lars suggested a way to show attachment buttons in
the header[2].  It looks much smart, so I'd like to try it when
I have time.

[1] Though it might be possible to display an inline PDF part in
    the article buffer by using docview.
[2]
<http://thread.gmane.org/gmane.emacs.gnus.general/83832/focus=83999>