QuadraticShaper is a basic quadratic or "square" function. A QuadraticShaper will default to IN_OUT, or SIGMOID,
however it can be set to be any of the three other modes. QuadraticShaper otherwise does not have any modifiers.
May be referred to as Tween.COSINE for use in setEasing().
QuadraticShaper()
QuadraticShaper( shapeMode )
QuadraticShaper( shapeMode, transition )
QuadraticShaper( shapeMode, transitionX, transitionY )
f(x){ x*x; }