[cairo] [RFC] Color space API (partial proposal)

[Adrian Johnson]

ecir hana wrote:
> - Not sure what good is to define color space in
> "cairo_color_space_create_device_n()" for if you are able to define
> alternative spaces in each of its colorant.

I see the problem with my DeviceN API now. The PDF tint transform 
function transforms n tint colors to m color components in the alternate 
color space. I'm not sure of the best way to define a cairo API for this.