Computation times

00:21.542 total execution time for 7 files from examples/04-lights:

Example	Time	Mem (MB)
Shadows (shadows.py)	00:07.757	0.0
Plotter Lighting Systems (plotter_lighting.py)	00:07.285	0.0
Light Types (light_types.py)	00:02.133	0.0
Beam Shape (beam_shape.py)	00:01.390	0.0
Light Actors (light_actors.py)	00:01.158	0.0
Attenuation (attenuation.py)	00:01.008	0.0
Disabling Mesh Lighting (mesh_lighting.py)	00:00.810	0.0