Small but important fixes

Version 1.0.5 and 1.0.6 bring some improvements over the jam release of ABGEFAHREN:

• better character controller, works now with low fps too
• improved billboards (NPCs and trees) so they rotate better towards the cam
• inside train: doesn't move any more if train is still at platform
• fixed the second exit on the platform
• fixed small glitch when trains appear