For lighting system introduced in v1.40

This mod . . .
- Adds choice of Halogen or LED headlights for Anthem, Cascadia, and 49x. 
(SCS includes LED headlight definitions; I made them available at the dealers.)
- For all SCS trucks
- Lengthens high beams' ranges.
- Widens low beams' angles.

Plan is to add some mod trucks after they're updated to v1.40. 

This mod does not affect accessory lights. 

