Make powerdevil normal executable instead of kded module
Summary:
This will allow kwin to grant permission to powerdevil which no other
application should have. Previously used kded module is now replaced by
the application which installs in LIBEXEC dir and started by desktop
file in /etc/xdg/autostart
Test Plan: Restarted session, powerdevil starts and all functions work perfectly
Reviewers: graesslin, broulik, Plasma
Reviewed By: broulik, Plasma
Subscribers: davidedmundson, shumski, plasma-devel
Tags: Plasma
Differential Revision: https://phabricator.kde.org/D2372