(Phewww!) I'm sure there are still things I missed...

I don't remember when was the last time I used them. Current Web Developer Tools do this already for you.

Color::updateRGBA ⟶ Color::updateRGB

Moved near/far values from MeshDepthMaterial to Camera (CanvasRenderer/WebGLRenderer/WebGLRenderer2).

A lot of things going on in this commit:

- added tangents computation for geometries
    - mesh must have UV coordinates
    - to be called explicitly once geometry is loaded like this: geometry.computeTangents()
    - tangents are stored in Vertex objects
    - quads are not solved properly (though workaround hack seems to work at least somehow, as far as each vertex appears at least somewhere)

- extended VBOs in WebGLRenderer to include tangent streams (when available)

- added "normal" shader to ShaderUtils (to be used with MeshShaderMaterial)
   - Blinn-Phong with one directional and one point light (7 varyings gone, just one spare)
   - normal maps are in tangent space
   - displacement maps use simple luminance value (could be changed if better precision is needed)

- displacement mapping uses vertex texture fetch
    - this requires GPU with Shader Model 3.0
    - not currently supported in ANGLE
    - for this, added "supportsVertexTextures" method to WebGLRenderer API, so that application can handle this

* Changed THREE.Vertex.positionScreen from a Vector3 to a Vector4 to support clipping.

* `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

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

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

Vector3.cross -> crossSelf
added Vector3.multiplySelf and others (kile)

Added THREE namespace
Camera.x -> Camera.position.x
Camera.target.x -> Camera.target.position.x
ColorMaterial -> ColorFillMaterial
FaceColorMaterial -> FaceColorFillMaterial
Materials are now multipass (use array)
Added ColorStrokeMaterial and FaceColorStrokeMaterial
geometry.faces.a are now indexes instead of links