Customize your knob!

A knob finishing off my Pixel Clock (see: http://jh-interact.blogspot.nl/2016/02/pixel-clock-introduction-preview.html)

The knob is customizable in different ways:
- Choose from base shapes cylinder or flower.
- For a cylinder you can choose the number of vertices to create a triangle, square, etc. Then a number of cylinders are subtracted.
- The flower shape consist of a number of cylinders, 'convex hulled' from the middle.
- Hole size to fit different axles. Provided are D-shaped and cylinder ('normal') shaped.
- And the depth can be adjusted for different sized axles.

A few examples are provided. Have fun!

"4-way ninja star"
SHAPE = "C";
CYLINDER_R_OUTER = 26;
ROUNDING_R = 1.5;
C_FN = 4;
C_CUT_NUM = 4;
C_CUT_R = 10;
C_CUT_OFFSET = 15;
C_CUT_FN = 5;
C_CUT_SCALE = 1;
C_CUT_ANGLE = 36;

"moon"
SHAPE = "C";
CYLINDER_R_OUTER = 26;
ROUNDING_R = 1.5;
C_FN = 12;
C_CUT_NUM = 1;
C_CUT_R = 15;
C_CUT_OFFSET = 22;
C_CUT_FN = 12;
C_CUT_SCALE = 1;
C_CUT_ANG