To be continued ...

todo:
- optimize vectors that don't need to be computed in shaders
- use material albedo
- add specular term
- wrapAround lighting (if possible)
- make attenuation parameters uniforms or defines instead of hardcoding them
- this is not using surface normal anywhere, this can't be right?
- maybe some box proxy instead of full-screen quad

See #2624

See #2803

And this should be it. Probably our longest standing bug. Relief ;)

It seems the mystery that was puzzling us for years were quaternion indices (Blender's wxyz vs ours xyzw which wasn't noticeable when using numerical indices).

Local rotations now already ok, still need to deal with global scene rotation.

See #2803

remove duplicate Quaternion.toEuler (already on Vector3.setEulerFromQuaternion), expand Quat unit test, fix merge.

Conflicts:
	test/sources.html

add new credits to Quaternion.js, expand Quaternion unit tests, move Matrix4 set* methods to standard file location.

Also more shader refactoring and unifications across light types.

Also unified wrapRGB in all lights to (1.0, 1.0, 1.0). Still need to figure out some way how not to have this hardcoded.

More code chunks sharing and naming unification. This should make easier to add new light types and to modify lights features.

Extracted common pieces of code into shader chunks.

Also here no need to recompute view space light position in shaders, uniform is enough.

The same like for spotlights slso here uniform for view space light direction is enough.

Sharing the same code for initialization and dynamic syncing. Also made directional lights work with hierarchies.

Moved view space light direction and position computations out of the shader.

These are constant for every pixel affected by the light, so computation can be done just once per light in JS and then passed in as uniform.

Todo:

- physically based specular
- wrap around lighting
- light cone proxy instead of fullscreen quad
- light distance attenuation
- move spot angle cos out of shader
- move light direction out of shader
- shadow maps

See #2624

This is the simplest way how to increase framerate in runtime (of course for the price of decreased visual quality).

Defaulting to 800 x 600 x 1.

This allows for API more compatible with WebGLRenderer (empty constructor followed by setSize).

Though for deferred renderer it's more efficient to specify width and height in the constructor (otherwise initial render targets are just going to be trashed immediately).