Skeleton for plane tests.
Use a plane instead of a sphere under most of the spheres.
Skeleton for plane.
Make sure the default constructed plane is correct.
Allow printing a ray.
Fix a bug in point3d comparison.
Allow construction from pre-normalised values.
Fix up some whitespace.
The general plane doesn't need to be movable.
Allow sub-classes to get access to the parent class.
Move dot products into their own file.
Change the implementation of scalar multiply so it works with ints.
Allow conversion of rays to JSON.
Add unary minus.
Implement ray/plane intersection tests.
Merge branch 'feature/plane' into develop