Saves keep comments and every byte they do not change. Faults in a scenery's
text are found and described. Files that change while the starter runs are
picked up without a manual reload.
A failed write leaves the old file in place. Settings that could not be read
are not saved over. UI exceptions reach the log. Started from a shortcut set
up elsewhere, the starter moves to its own folder when only that one holds a
game.
VehicleDatabase becomes VehicleCatalog, Physics becomes VehiclePhysics, and the
textures.txt and .fiz parsers move to Infrastructure. GameLibrary replaces the
GameData singleton.
