- Change to a system instead of a user service. In the general case (single user machine) we want this service to run from boot to shutdown, not only on user session. Using a user service forces users to enable lingering to achieve that. This change also removes the need for specific udev rules / plugdev group.
 - Enable more hardening options.
 - Add support for optional /etc/default/linux-thermaltake-rgb file (can contain DEBUG=true).
 - Add delay between restarts.
 - Change back executable path to the default /usr/bin. It is downstream packagers job to adapt the service file if they don't deploy to the standard location.

Signed-off-by: Julien Nicoulaud <julien.nicoulaud@gmail.com>