bug#57779: 29.0.50; Make thumbs.el obsolete

[Stefan Kangas <stefankangas@gmail.com>]

Severity: wishlist

In Bug#10758, I argued that:

> I guess we could rebase thumbs.el to also use the built-in image viewing
> support, but I took a look and this external conversion seems built into
> the foundation of how that library works.  So this looks to me like it
> would amount to a rewrite of thumbs.el.  I could be wrong of course, but
> that was my conclusion after poking at it for an hour or so.
>
> Furthermore, at this point, image-dired.el is by far the more powerful
> package, and it seems better implemented overall.  Although it borrows
> heavily from thumbs.el (or at least it used to), thumbs.el seems fully
> redundant these days. ...
>
> So rather than attempting a rewrite of thumbs.el, the better solution
> seems to me to add any important missing features from thumbs.el to
> image-dired.el, and then obsoleting the former (not necessarily in that
> order, but either way is fine to me).
Ref: https://debbugs.gnu.org/cgi/bugreport.cgi?bug=10758#26

Now that we have added the `image-dired-wallpaper-set' command to
image-dired, I have a hard time seeing what thumbs.el provides over
Image-Dired.  I don't think it's worthwhile to continue maintaining
both.  Also, thumbs.el has seen very limited development in the last
decade or more.

I therefore suggest that we make thumbs.el obsolete, to better focus our
efforts on image-dired.el.