Optional syntax highlighting in theme editor

[hameau]

I think this should be optional, just like the rich editor.

I agree with this.

While I understand that there are situations where it may be useful, it breaks It's All Text (Firefox plugin) unless Javascript is disabled (which in turn breaks so much back-end functionality). Additionally, theme components and admin header/footer sections don't benefit from syntax highlighting, which makes it an incomplete feature, too.

I was somewhat surprised to see this get in to core. It's better suited to a plugin, imo.