Feature: Point : tangent spline & line

[Onetchou]

Add a tool to find the tangent point between a line and a spline.
For patternmaking sake, at first, the tool could only draw the tangent point which is the closest to the line base point (if it exists), it'll solve most of the cases where this feature is needed.
In a advanced version the software could ask which tangent point to draw if it has computed many of them.
See this thread on the forum.