Added examples for Cartesian2 and Cartesian3

Signed-off-by: Matjaz Drolc <mdrolc@gmail.com>

This is part of #651. Added examples for:
Cartesian2.magnitudeSquared
Cartesian2.magnitude
Cartesian2.normalize
Cartesian2.dot
Cartesian2.multiplyComponents
Cartesian2.abs
Cartesian2.lerp
Cartesian2.angleBetween

Cartesian3.fromSpherical
Cartesian3.magnitudeSquared
Cartesian3.magnitude
Cartesian3.normalize
Cartesian3.dot
Cartesian3.multiplyComponents
Cartesian3.abs
Cartesian3.lerp
Cartesian3.angleBetween
Cartesian3.cross