Major backend rewrite with vastly improved support for devices.
- All devices can now open the Custom Editor, even if there's no specific layout available.
- Add various specific layouts to the custom editor (incl. Firefly and some mice).
- Support all LEDs available on newer devices (side LEDs, etc.)
- Support non-standard polling rates
- Restore current effect and colors on open
- New translations: Dutch and Russian
- Various other smaller changes