fix auto fences being built on the wrong side

fix errors when removing one terminal

new self-splitting tracks coz the game does not handle 2.5m tracks well

tolerate errors when rejoining neighbours + fix joining subway to 12-track station

make compatible with build 35716, which introduced an error (newly assert that no nodes are in the same location + add no matching fixes to the construction logic).

fix mesh era_c_sattion_sign_lod0

6 new stations from the game (era c) + little makeover

bugfix + some refactoring

Some fine points for edge cases

prettier pedestrian tubes