Add a method to BoundingVolume that tells if they are touching, penetrating, or disjoint.

[sebcrozet]

This method of the BoundingVolume trait would return a three-variants-enum that tells if the bounding volumes are exactly touching, penetrating, or disjoint.

I do not know what name such method should have though.

[fourbytes]

+1 for this, would be quite helpful.