Roofbar for Renault Premium v1.1

Changelog:
v1.1: Mod redone using the variant system, reduced size; added new slots
Compatibility: ETS 2 v1.27.x Mod will not work with earlier game versions!
Mod adds a roof bar fitted to for both Renault premium cabins.

Features:
- steel/chrome/paint variant for high cabin
- steel/chrome/paint variant for low cabin
- 10 main slots for lamps/horns etc.
- 7 slots for marker lights
- additional variant for small cabin: 8 main slots, 7 marker slots; compatible with the front roof mirror
- [v1.1+ only] 4 extra slots for cabin mounted air horns/beacons (both cabins)

Supported trucks: SCS vanilla, Renault Premium rework by Schumi, others not tested, should work with any mod using default SCS definitions for the truck.