performance impact should be negligible eitherway and rotation does
certainly make for the smoothest result.

• uses a reference image that remains unchanged to rotate from. continued rotation of the same image would degrade the quality eventually turning the image into a blur after a couple of spins and make it outright disappear after a while, hence the reference image
• from 4 spriteimages down to one, which is always the visible one
• SpriteImage has a new setter to change the image while also updating forwarded properties (in hindsight these should have bee functions to begin with)
• reference images gets rotated over 2*π*timebooted (no mod since we can rotate by arbitrarily large radians anyway)