Optimised Particles projection in CanvasRenderer.

Most of the examples working.

Almost done porting CanvasRenderer to the new material system (plus some performance gains on the way :D)
`Color` now handles hex with no alpha byte (probably there is a nicer way of doing it...)

Experimenting with different syntax for materials (just hex instead of THREE.Color in API), checking how it feels with shaders example.

First attempt at MeshBasicMaterial / MeshLambertMaterial / MeshPhongMaterial. Also: testing branching :)

This is not supposed to work yet, all is in the flux, do not base any code on this.

* THREE.Rectangle: `_x1`, ` _x2`, `_y1`, `_y2` ⟶ `_left`, `_right`, `_top`, `_bottom`

TODO: still could save some more multiplication by precomputing offsets for individual components of the elements.

At Loader.js, as far as I can see we don't need all that `stride` stuff.  Removed/Simplified from createModel() by now. That saves *a lot* of multiplications at init of the geometry.

Tested exporters with new Blender 2.55 Beta. It seems both old and new one work without any changes \o/

Such broken materials will be replaced by dummy materials names like this "undefined_dummy_5".

Fixed crash bug with non-textured models in new Blender exporter.

Fixed bottom alignment bug in OBJ converters.

Models exported by this version should be loaded like this (the same as for slim OBJ converter):

    var loader = new THREE.Loader();
    loader.loadAscii( "path/to/model/Model.js", function( geometry ) { createScene( geometry ) }, "path/to/model" );

Compared to OBJ converter, currently only single mesh is exported (many models are composed of several meshes).

TODO
    - model alignment
    - copy used images to folder where exported file goes
    - export all selected meshes / all meshes in the scene?
    - binary format

Refactored OBJ slim converter (to make it easier to reuse ASCII converter snippets in Blender exporter).

Added a little sanity check in binary format loader (commented out debug log of computed total file size which should match with real file size).

Optimized binary model format to use indexed UVs. Updated OBJ slim converter and Loader accordingly.

This saves about 10% from size of textured binary models.

* AUTHORS: Just realised there is a github page with that info already. https://github.com/mrdoob/three.js/contributors