[Fixed 1.05][Bug 1.03] I broke the conveyor belts

I noticed that the conveyor belt routing algorithm is behaving a bit odd, so I started playing around with it.

If I have n outputs linked with m inputs, a car is routed to the nearest free m. If no free m is available, the cars are all piled up in front of the m that was last added instead of evenly distributed between all m, or placed in front of the m that has the shortest queue or will be available in the shortest time (which is a bit tricky to approximate).

However, I also managed to created a layout that breaks the game, i.e. reproducibly crashes it as soon as the chassis are assembled. The whole factory is one big bus that has every slot take from and put its output back onto. I put the save here: pastebin.com/R0m4ZeJU

Thanks for this. I am working on a fix with that save game as an example right now. Sadly the next patch (currently uploading) will not contain it, but it should be there in the one after that…