Vector2 reorganization, returning 'this' on mutable operations
Bounds2.transform/transformed not creating as many extraneous objects
Adding note about cssTransformStyles
[BREAKING CHANGE] Matrix3 operator renaming:
rotation() => getRotation()
determinant() => getDeterminant()
translation() => getTranslation()
scaling() => getScaleVector()
Adding Matrix3 ES5 getters for changed properties
[BREAKING CHANGE] Renaming cssTransform, svgTransform, cssTransformStyles, adding ES5 getters