[patches] Add a color management framework to weston

[Bill Spitzak]

Richard Hughes wrote:

> For GIMP I was going to just allow the app to opt-out a sub-surface
> from any kind of color management. i.e. do it all in the app.

Maybe the client should be able to query the color space of the output 
and can set the color space of it's buffer to the same one, this would 
indicate that no color correction is needed. The compositor could still 
color-correct it from one output's color space to another's if it is on 
multiple outputs.

Ideally a client should be able to do this with just some strings (ie 
query the color space and send the same string as the buffer's color 
space) so it does not have to open a CMS library that it might otherwise 
not be using.