bug#19903: 24.4; wrong-type-argument symbolp "bold" during enriched-encode

[Eli Zaretskii]

> From: Ivan Shmakov <ivan@siamics.net>
> Date: Fri, 20 Feb 2015 09:12:08 +0000
> 
>       If string faces are rendered just the same as symbol ones,
>       I’d rather wonder if either facemenu-add-face should silently
>       ‘intern’ all the strings it gets before use, /or/ face-attribute
>       should do that.  (Or perhaps both.)

Patches to do that are welcome.

Thanks.