Polygon-Möbius-Strip Customizer

Takes a regular polygon and revolve it about an axis exterior to the polygon, creating a toroidal solid, while rotating the polygon about its center as it revolves.

Customizable, so you can change:
* number of polygon sides 'N_gon'
* number of twists 'Twist' per ring rotation
* Ring and polygon diameter
* Thickness (for Möbius Strip only)
* angular section to print
* Rotation orientation of polygon
* Internal thorical hole (if any + diameter)

Some examples:
mobius_polygon(N_gon=n,Twist= 0) is just a non-twisted ring (toroid) with an n-gonal cross-section and approaches a torus as n goes to infinity.
mobius_polygon(2,1/2) is the classic Mobius strip.
mobius_polygon(6,6), has n-surfaces and n-eges, all identical, spiraling around each other.

Inspired by http://twistypuzzles.com/forum/viewtopic.php?f=7&t=27711&hilit=mobius and
the remixed source by kitwallace!

Todo list:
* DONE: add option to print just a slice => implemented mypie()
*DONE made a bit faster using