Roman Gilg authored Jul 25, 2018 and David Edmundson committed Aug 05, 2018

Summary:
Extends the output device and output configuration interfaces with the
ability
to query and set the RGB color intensity curves (gamma ramps) of the
associated output.

Test Plan: Manually. Auto tests will be added to this diff soon.

Reviewers: #frameworks, graesslin, romangg

Subscribers: kde-frameworks-devel, graesslin, davidedmundson, zzag,
cfeck

Tags: #frameworks

Differential Revision: https://phabricator.kde.org/D12388