[patches] Add a color management framework to weston

[Bill Spitzak]

Richard Hughes wrote:

> I've got to move onto other stuff next week, but I'd be really
> interested if anyone has inputs on how the sub-surface gamut mapping
> using shaders is going to work. The main complication seems to be that
> it's per-output, rather than per-surface. I've played with 1bit masks
> in the past, but this made the shader quite complicated. Ideas very
> welcome. Thanks.

The compositor should be able to draw N polygons for the N intersections 
of a surface with each output, each using a different shader?

You absolutely do not want to put an if based on a pixel value into a 
glsl shader. It is really slow.