Update existing Paths with current settings

[arandomollie]

Reprocess existing paths using current settings
Somewhat adds to #14 as can use start and end points from that
Useful for amending cant on individual lines on multi-track segments, backwards compatibility if new features added to take advantage of, switch model of existing path to new model, etc.

[anthony0br]

You'd need to save a history of all the node data somewhere

Which could actually be useful for other things too

[arandomollie]

You wouldnt, could find outer two segments in rendered curve and use those to reconstruct original control points

[anthony0br]

You’d have to adjust the render code to make the first and last segments exactly aligned with the nodes if they aren’t already, since bezier doesn’t do this

[anthony0br]

But this might affect the quality

[arandomollie]

would only need to amend start, end segment is already aligned with node
in that case, can just raycast to find an end node where applicable
plus in general a small alignment issue wont cause a problem