[mythtv] Aspect/Zoom Override Menu UI

[Robin Neatherway]

> I've talked before about the need to separate aspect overrides from the
> zoom modes. Outside of Australia we detect the true aspect ratio most
> of the time, but zoom modes are not easily detected. If the zoom mode
> were separate it would only have 3 items: no zoom, letterbox zoom and
> fill. Aspect override would have 3 items: use detected aspect, use 4:3
> and use 16:9...

FWIW, I think this would be a good idea.

Robin