Parametric spiral generator

OpenScad's rotate_extrude module has a few limitations, particularly in the version I have. Later versions have addressed the lack of an angle parameter, but I needed something similar to how linear_extrude can do twist and scale, and to generate spirals by offsetting the shape during the rotation.
A comment on a forum somewhere (sadly I don't remember where) suggested using the hull module to accomplish this, which turned out to be an effective method. I kept on adding features, because frankl