color management: protocol fixes and color_space_creator object
- creating a color space now leads through the color_space_creator object which allows us to fail at ceating the color space
- there are now three ways to create a color space. From an ICC profile, from well-known names and parametrically.
- multiple color_management_outputs can now be created for a single wl_output
- color_space_changed is not send when the object is created anymore
- clearify that destroying a color space has no effect on the color space state associated with surfaces and outputs