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

Changed OBJ -> Three.js converter to use new materials system (eventual old models need to be reconverted).

Limitations:

  - one use case is now much slower
    - when a mesh has each face with different color (e.g. polyfield in examples/test.html)
    - before this used FaceColorFill material and in WebGLRenderer it was rendered fast with color attribute array
    - now when FaceColorFill material is gone, each face gets own VBO :(

  - material sorting uses Materials "toString" methods for hashing, so it's very important to keep these in a good shape

In Chrome it looks more or less ok, but it has some problem in Firefox 4 (with some camera angles there are black areas around edges).

Also updated Python builder scripts and examples to include this new material.

Changed camera matrix update in WebGLRenderer to happen just once per frame, no need to do it with every object.

* MeshBitmapUVMappingMaterial -> MeshBitmapMaterial. Second param is mode, which is THREE.MeshBitmapMaterialMode.UVMAPPING by default.
* Removed MeshFaceColorFillMaterial and MeshFaceColorStrokeMaterial
* Added MeshFaceMaterial ( it uses the face.material for that pass )
* CanvasRenderer and SVGRenderer per face material logic changed.
* SVGRenderer supports particles again.
* WebGLRenderer currently broken :/
* Code clean up

Premultiplied alpha in WebGLRenderer for MeshColorFillMaterial and MeshColorStrokeMaterial (to get closer to CanvasRenderer look).

Refactored multimaterials to also work with non-textured models composed from multiple material groups.

Old version was doing massive overdraw (whole mesh was drawn for each material).

Even current solution is still quite messy: there is a different behavior for stroke and fill materials (when used as secondary materials).

Stroke materials are applied to the complete mesh (as most common use case seems to be wireframe) while fill materials now apply only to faces within single material group (when "decalIndex" property of secondary fill material is set).

There were two problems:

- vertices were in a different coordinate system than normals
- generated JS code was not properly handling normals with 0-sized components

Changed exported JS class name in OBJ converter to use the same convention as Blender exporter (use exact case of JS filename, no capitalization).

Changed WebGLRenderer to use 3x3 normal matrix.

Limitations of WebGL lights:

- currently handles only single one of each ambient/directional/point light
- light intensity modifier not yet taken into account
- only diffuse term (this applies also in CanvasRenderer)

Added rudimentary 3x3 matrix class (just transpose, as this is needed for normal matrix).

Changed mesh JS class name generator in Blender exporter to use cross-platform path parsing.
Old version was generating broken class names on Windows (full path was included).

Old version was generating broken class names on Windows (full path was included).

Added multipass multimaterials to WebGLRenderer.

Refactored WebGLRenderer shader to become proto-mini-ubershader (untershader :).

Line width is currently not set properly on Chrome in Windows:

http://code.google.com/p/chromium/issues/detail?id=60124

* Updated TODO

* Added Blender 2.54 exporter. (Crossing fingers so they don't change the scripting system again...)

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.

Experiment to get backwards compatibility with the original meaning of materials array in Mesh (= extra materials are drawn for whole mesh).

Limitations:
 - works just in CanvasRenderer
 - doesn't work for MeshBitmapUVMappingMaterial as secondary material

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

Using projection * view * obj matrix to transform vertices in Renderer instead of transforming twice (once by view * obj and once by projection).