...to support an arbitrary number of connections for rails, which leads to these new features:
- switches now get recognized by the trackworker correctly
- ability to add real rail crosses
During this, I also rewrote the rail registering system and the conway function (important part of path prediction)
Note, developers: the track preset format changed, you might need to rewrite them according to the presets in tracks.lua if you wrote your own
(possibly breaks advcarts)