Thomas Woolford opened merge request !572: brightnesscontrol: add support for ambient light devices supported by iio-sensor-proxy at Plasma / PowerDevil

I've taken Fuschan Wen's !199, rebased it on the current master branch, and applied a few fixes to get everything compiling again.

To test, run

qdbus-qt5 org.kde.Solid.PowerManagement /org/kde/Solid/PowerManagement/Actions/BrightnessControl setBrightnessMode 1

If your device doesn't have a supported ambient light sensor, run autotests/mockiiosensorproxy.py with root permission to create >a mocked dbus interface.

I'm pretty new to KDE dev, so please let me know if there's any parts that need fixing up, I'm happy to take it on.