Extended CanvasRenderer to be able to handle decals (MeshBitmapUVMappingMaterials as secondary materials).

For decals you need to set "decalIndex" property of the material (corresponding to materials index of the original mesh UV material).

Added multimaterials example.

Fixed forgotten sphere smoothing in OBJ converter example.

Added OBJ converter test example.

Modified Three.js to handle converted models:

 - extended WebGL renderer to use texturing
   - broke down model into multiple VBOs according to materials
   - textures are lazy created when images get loaded
     (converter takes care of resizing images to nearest power of 2
      dimensions using 2d canvas)

 - changed material array semantics in Mesh object
    - before: multiple materials were applied to all faces (broken in WebGL, needs multitexturing shader)
    - now: there is only single material per face, but one mesh can have faces with different materials

 - added per vertex normals (to get smooth shading in WebGL)

* `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

- `three_debug.js` checks for broken UVs and display these faces with pink color instead

* `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

* Removed SVG rgba() workaround for WebKit. (WebKit now supports it);

- Added (mandatory) video example
- Restructured examples folder

- Added wireframe view on VR demo

+ Expand UVs (this should fix the glitches)

- CanvasRenderer supports TextureUVMappingMaterial.
- Moved UVs to Geometry.
- Minor clean up

- Added Object3D.autoUpdateMatrix

+ Workaround for WebKit not supporting rgba() in SVG yet
+ Aesthetic changes on the readme file