bugfix

add features to change bridge, track and tunnel types

optimise some lods and the stone bridges

neater pedestrian bridges + more options for walls

Easier use of pedestrian paths, lifts and stairs + bugfix

overhauled the bridge with glass shields

New stone bridges

fix a rare crash linked to a mesh + improve dirt

many meshes and materials optimised + new walls

draw auto fences on the correct side + add small adjustments