bug#7651: 23.2.91; Rmail doesn't allow displaying text attachments conveniently

[Eli Zaretskii]

> From: Kenichi Handa <handa@m17n.org>
> Cc: 7651@debbugs.gnu.org
> Date: Fri, 07 Jan 2011 16:13:11 +0900
> 
> As we can toggle all entities, to be consistent, we must
> have toggle buttons on all entities.  But, I think it
> results in a little bit annoying display.  So, how about
> making each content-type string (e.g. "text/plain",
> "image/png" in tagline) a button instead of having "Toggle
> show/hide" button?

That would be okay, too, but since those buttons' visual appearance
has no cue to the fact that they are buttons, we should either change
their visual appearance, or maybe add some textual hint, like
"[1:text/plain (RET to show/hide)]".

I also don't think adding a "Toggle show/hide" button would make the
display annoying.