Color management and HDR protocol

Maintainers:
Sebastian Wick <sebastian at sebastianwick.net>
Pekka Paalanen <pekka.paalanen@collabora.com>


Historical credits not mentioned in the first commit:

- Niels Ole Salscheider, for an early protocol version
  https://lists.freedesktop.org/archives/wayland-devel/2014-October/017755.html
