This adds 2 extra parameters to SpotLight:

- "angle" for controlling light cone width
- "exponent" for controlling sideways light attenuation (from light->target axis towards edges of light cone)

Warning: this changes appearance of everything that used old fake SpotLight. To get approximately similar look use these parameter values:

```
spotLight.angle = Math.PI;
spotLight.exponent = 1;
```

Todo:

- implement spotlights in normal map and skin shaders
- check what's going on with vertex colors and ambient term in unlit parts
- check shadowmap darkening vs unlit parts darkening
- maybe some better formula for light cone attenuation, current one varies too wildly with cone angle

Commented out WebGLRenderer console.log (not really useful anymore) and added new console.logs on all renderers (hopefully more useful).

Hmm... I'll need to rewrite this one, the result seems to be wrong.

take 2: the 'fxaa' shader busts the transparency, so I'm setting the transparency to the transparency of the "middle" pixel instead. Changed after comment by alreredq - now the middle pixel is only fetched once.

wanted to fix the + 0.001 issue in `THREE.LatheGeometry` but ended up fixing, rewriting and cleaning up quite a bit of it. I think the UVs now looks better (using webgl_geometries.html) but UV behavior is slightly different so beware (although it should be difficult to support non-complete wrapped lathe UVs). UVs + mergeVertices + subD should be looked at another day, but that will be another issue.

making SubD code a little more readable. problems with UVs seems fixed. only the LatheGeometry subdivision example fails. other geometry seems to be working ok.