OpenSCAD helical extrude and thread library

Here is a universal helical extrude library for OpenSCAD I wrote a while ago.
You can extrude any polygon in the form of [[x1,z1],[x2,z2],[x3,z3],...]
It has 5 different helix generation modes:
pitch / height
pitch / revolutions
helix_angle / height
helix_angle / revolutions
revolutions / height

I also added a little thread library that uses the helix_extrude module.

Both libraries are ready to use if you have deleted the example line.