- address some bezier track z fighting
- portable storage interfaces now stay connected until a contraption departs
- seats can now collect entities when collided with on a contraption
- clicking on seats now tries to mount any leashed mobs first
- fixed seated entities not staying on seats on disassembly. this probably also fixed issues with sub-contraptions (oops)
- fixed portable storage interface not working on train contraptions
- Trains can now travel backwards through the graph
- Controls are now a requirement for assembly
- Double-endedness now depends on two opposite controls blocks anywhere on the train
- Players can now manually control trains via a mounted controls block
