The old starter looked a vehicle up by folder, skin and model. The folder was
left out here, and 39 skin names recur across folders - "red" is a Clio, an
Audi and a crane - so a vehicle could get another folder's livery.
The ET42-026 dresses both halves in 112E-026 and the scenery tells them apart
by the model. Textures were keyed by the skin alone, so the B half became a
second A: not part of the set, and listed on its own. A shared skin now gets
the model in its id, vehicles are looked up by skin and model, and the
vehicle cache is rebuilt for the new ids.
VehicleDatabase becomes VehicleCatalog, Physics becomes VehiclePhysics, and the
textures.txt and .fiz parsers move to Infrastructure. GameLibrary replaces the
GameData singleton.
