A number of things need to happen to make the a11y themes work acceptably:

- We need working gtk2 themes. We could either convert gnome-themes back to working with gtk2 and gtk2-engines, or move the a11y theme parts over from gnome-themes to gnome-themes-standard. I think the latter is going to end up being cleaner.

- The new control-center and other a11y controls make the assumption that gtk-theme == icon-theme, and ignore other metatheme components (at least for now), so we need to have a matching icon theme with the same name) for each a11y theme. For the HighContrast theme, the HighContrast-SVG theme in gnome-themes is a good starting point. It can probably mechanically converted into a HighContrastInverse theme too. For LowContrast, I don't know atm.

- The index.theme files are no longer used by anything. They are just a distraction (and cause extra translation work), and we should ditch them.