Color and dynamic range management

This issue is for tracking progress on upstreaming color and dynamic range management for weston.

• The protocol discussions are here wayland-protocols!14 (commits)
• dynamic range management requires further discussions
• A proof of concept implementation is here https://gitlab.freedesktop.org/swick/weston/tree/color-management-rebase

• improve sharing of ICC files !240 (merged)
• assign color spaces to the heads before enabling the output
• implement modules (static, colord) to load color spaces
• compositor plumbing to enable/disable color management
• basic ICC vcgt support
• implement the protocol and extend the surface commit state
• lower color space conversions to a 3D LUT using lcms2
• extract linearization LUT from output color spaces
• gl-renderer changes
  • gl-renderer tests to make sure we don't break everything
    • !344 (merged)
    • !287 (merged)
    • actually test different buffer types, formats etc
  • 3D LUT support for color space conversions
  • gamma correct blending
    • fp shadow buffer and/or GL_EXT_shader_framebuffer_fetch_non_coherent
• only assign surfaces to planes when the color space matches the output
• shared CRTC clone mode only for heads with the same color space