Reorganised interpolators.
Added a base Interpolator class.
Added mappings to interpolators.
Added accelerate mapping.
Added reversed mapping.
Added circuit mapping.
Added accelerate-decelerate mapping.
Reorganised mappings.
Removed useless argument.
Changed Interpolatable to make it similar to linear combinations.
Added a linear interpolator.
Added a quadrtic Bezier interpolator.
Added a cubic Bezier interpolator.