bug#47074: Replace XPM icons with Unicode codepoints in customize/widgets

[Eli Zaretskii]

> From: Stefan Kangas <stefan@marxist.se>
> Date: Thu, 11 Mar 2021 11:51:40 -0600
> Cc: 47074@debbugs.gnu.org
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > With Symbola as the font (which is what we have by default), the
> > result is much worse than images.
> 
> :-/
> 
> So I guess using Unicode would need to be optional.

Yes, I think so.