Sum and difference bodies

[b-butler]

Description

Taking the sum or difference body of two shapes in 2D or 3D would not be difficult to implement and would be a nice feature. This could use duck typing to work with 2D or 3D vectors as well. I would recommend overwriting the __add__ and __sub__ methods of Poly classes for this.

Tasks

• Create functions to calculate the sum and difference body and wrap results in the correct object
• Use these functions to allow shape1 + shape2 and shape1 - shape2
• Document these function
• write unit tests for these functions