TODO

* 2012-10: Transformation : add a dirty flag to control
  . if a local matrix must be updated, or not;
  . if a matrix should be update depending on the dirty flag of its parent.
* 2012-10: Improve lights model. Write real shaders.
* 2012-10: Add custom attributes.
* 2012-10: Rename projection matrix nodes to more consistent names.
* 2012-10: Rename FaceObjectNode, FaceCameraNode and TranslationCompensatorNode with more explicit names.
* 2012-10: Create a high level Skybox object (based on what is done in earth sample)
* 2012-10: New concept : SceneLayer !
* 2012-10: Add a new loader which concatenate source chunks to produce shaders (allowing to share code, like lighting).
* 2012-10: Add 2 phases rendering for transparent objects : CW faces then CCW faces.
* 2012-10: Add parameters for blending mode for transparent material.
* 2012-09: AJAX loader for shaders
  . program descriptors in JSON format, even in text nodes of the HTML doc
* 2012-09: Bindings autodetection
* 2012-09: Geometry Loader from JSON data streams
* 2012-09: Exporter Blender
* 2012-09: Multi material meshes