ETS2 - Semitrailers Pack

Changelog
Updated to 1.48.5 patch

This Pack adds 4 new 12.50 meters Semitrailers:
- Bartoletti Flatbed Semitrailer
- Bartoletti Dropsides Semitrailer
- Bartoletti OSB Dropsides Semitrailer
- Viberti Curtainsides Semitrailer.

Authors: Ralf84