Hi! I did separate the "reference path" and the "generating path" in lpe-vonkoch.

I think it makes the UI more clear, but it changes previous conventions of course (the last segment of the old generating path should be cut/pasted into the new "generating path"). Caution: this might change again. As it is supposed to contain only one segment, the "reference path" could/should be replaced by 2 points (on the other hand, it might be more convenient to be able to move both points at once, copy/paste that segment, etc..., so I'm not sure what's the best here).

I also modified the tooltips, and parameter order, trying to follow your remarks. Thank you Alexandre P. and joncruz. Please review it again...

Bye, JF.