A shape's rotation value keeps growing as you spin

As youi rotate an object with the shape.rotate(degrees) method, the rotation() value of the object grows continually as you spin. It would make more sense to have it "capped" at 360, and display the rotation relative to the 0-360 degree map, not just as the sum of past rotations.

I think this should be fairly easy to implement. We just need to make the rotation value equal to the current value mod 360.

shape.rotation() = shape.rotation() mod 360