[development] Move multiple theme per site support to contrib module

[andrew morton]

On 6/6/06, Adrian Simmons <adrinux at perlucida.com> wrote:
> Adrian Rossouw wrote:
> > How many people actually use user specified themes on their sites?
>
> Not me, not 'users' as such anyway. I do use this functionality when making
> new themes though. The admin account gets it's theme set to a working theme,
> whilst anonymous and themedev users get the default
> new-theme-in-progres-which-might-be-broken.

I use the feature similarly. Anonymous users get a "pretty" site theme
that doesn't display the admin or editing features correctly and
authenticated users get bluemarine. I seem to remember that the
difficulty of theming the admin pages was listed as one of themer's
biggest frustrations in one of those admin surveys.

andrew