Pushed REVISION to 29.

* Added the first WebGL example to README \:D/

* Cleaned interactive_cubes example code.

* Fixed a bug in Ray.intersectObject: face.normal needs to be transformed using matrixRotation otherwise rotated objects fail
* A bit nicer example

Unimpressive example added `interactive_spheres.html`

* Minor fixes (Geometry normal calculation)
* Isolated Matrix3 code into `Matrix3.js`
* README and TODO updated

* `CanvasRenderer` and `SVGRenderer` basic lighting support (`*ColorStroke`/`*ColorFill` only)
* `Renderer` > `Projector`. `CanvasRenderer`, `SVGRenderer` and `DOMRenderer` do not extend anymore
* Interactivity base code (hdi folder). To be refactored... ([mindlapse](http://github.com/mindlapse))
* Added `computeCentroids` method to `Geometry`
* Included `Stats.js` directly in the `/examples` folder to avoid the need of internet for playing around

- Minor tweaks

* Additional `Matrix4` and `Vector3` methods

- Camelcased the minified files (it feels weird both ways anyway...)

- Face4 with MeshBitmapMaterial gap fixed

* `Face4` now supports `MeshBitmapUVMappingMaterial`
* Changed order of `*StrokeMaterial` parameters. Now it's `color`, `opacity`, `lineWidth`.
* `BitmapUVMappingMaterial` > `MeshBitmapUVMappingMaterial`
* `ColorFillMaterial` > `MeshColorFillMaterial`
* `ColorStrokeMaterial` > `MeshColorStrokeMaterial`
* `FaceColorFillMaterial` > `MeshFaceColorFillMaterial`
* `FaceColorStrokeMaterial` > `MeshFaceColorStrokeMaterial`
* `ColorStrokeMaterial` > `LineColorMaterial`
* `Rectangle.instersects` returned false with rectangles with 0px witdh or height

* `Particle` now use `ParticleCircleMaterial` instead of `ColorFillMaterial`
* `Particle.size` > `Particle.scale.x` and `Particle.scale.y`
* `SVGRenderer` currently out of sync

- Matrix4.lookAt fix (CanvasRenderer and SVGRenderer now handle the -Y)
- Color class now using 0-1 floats instead of 0-255 integers

- Enabled Scene.removeObject
- Removed computeNormals() from Geometry

- Simplified lookAt in Matrix4
- Added cross() in Vector3

- Object3D.overdraw = true to enable CanvasRenderer screen space point expansion hack.

- Fixed overdraw when using stroke materials