v0.3.0

This release refactors several intersection methods and adds new intersects(with:) -> Bool methods for better API usage when the caller only cares if things intersect (without caring about the intersections themselves).

It makes public the Flatness API for determining the maximum distance a Bezier curve strays from the line segment connecting its endpoints.

It renames "threshold" parameters to the more descriptive "accuracy"

It has several other miscellaneous renamings.