OpenSCAD Parametric Pulleys with mount holes derivative from 16627

This is a derivative of the parametric pulleys from thing 16627, but, with the option to add mounting holes into the pulleys.

I need this specific option for a pulley from my thing 99132 Lenz2 Helical XL.

Also added the option to have the set screw in the belt profile, you might need to adjust the angle to fit nicely on top of a tooth.

Update 1-4-2017: Added option for a cavity in the pulley and mounts for flat magnets for RPM measurement. An option for a closed base pulley is as ea