Greg's Wade reloaded - Guidler, Tilt Screws, Fishbone Gears, Parametric Filament

This is a modification to jonaskuehling's version of the famous Gregs Wade Extruder. I am participating in a 18 unit Prusa group build (using TOMs primarily to print the parts!) We wanted this version, but need both 3 mm and 1.75 versions. I noted as others that the filament path wasn't completly parameterized and that the guidler moves in Z. I believe I have solved the issue, you can read my comments, any code changed by me has a //DEC comment. I have printed a 1.75 mm version, and it seems cor