Bug 780375 - Color picker won't pick on Wayland.
Add support for KWin API, for KDE on Wayland. Unfortunately though, KWin's "pick" API seems to have failures, so I fallback to the default color picking when this happens. This will still not work on Wayland, but at least won't cause regression for color picking on KDE/X11. See also KDE bug: https://bugs.kde.org/show_bug.cgi?id=387720