ok, this is a 'hack'ish solution:

- it uses the previous segments angle to 'continue' forward, since the angle is updated earlier in the update loop, and this angle is set to point towards the next segment.
- since it just 'continues' without a given delta value (this calculation is done in the wrong place I think, should be moved to the update-loop with a delta value.), it does not now how far / fast to move. (I just gave it a magic number '4', it seems to work :p)

it adds a per segment boolean (tail.goingThroughWall), instead of a boolean for the whole snake, as normally (most of the time) you want the segments to move towards their parent / segment in front at a normal pace. only when it crosses a line does that segment jump to the top. (when a segment has jumped, it means the angle for the next segment is going to basically reverse, but for this special case I use the angle of the segment behind it.)