Added dimensionality.

Specific models now inherit from a dimensionality. These dimensionalities include:

  ZeroDimensional
  OneDimensional
  TwoDimensional
  ThreeDimensional

 Dimensionality is meant to confer specific methods that only make sense in the context of certain objects.

 For example with circles or rectangles, the TwoDimensional parent class will confer translational sugar methods such as:
 up, down, right, left, forward, and backward. These methods manipulate the TwoDimensional child instances anchor.