Remove redundant normalize() in Vector3.html (there were two). Other
additions.

Renamed ShaderLib's 'normal2' shader to 'normalmap' as suggested in 4276c9f5.

ShaderUtils relied on ShaderChunks so this created troubles when trying to use three-canvas and three-extras. Besides, better to keep a single library of shaders.

This is a formatting commit, it removes an unnecessary else branch.

The functionality removed is repeated directly after this code block.
The entire process is actually being done twice, which is undoubtedly incorrect or otherwise very unclear.

Given that it is simply doing 3 actions:

a) Adjusting the pitch/yaw based on the mouse position deltas, then multiplying that by the lookSpeed.
b) Clamping, transforming the pitch space (to the X,Z coordinate frame) and then converting the pitch/yaw (lat/lon) to radians.
c) Calculating the target position 100 units in the direction specified by the pitch/yaw.

This process has no reason to be repeated.

CanvasRenderer+SVGRenderer: Removed 2D clipping for Face3/Face4 elements as the projector is already taking care of that.

However, this can create glitches on extreme cases when the polygon is inside the frustum but the vertices are not.
Maybe this can be achieved with Box3 in a performant way?
/ping @bhouston

SoftwareRenderer: Fixed the distortion bug and experimented wth a hacky way of passing different "materials" to the rasterer.

Sadly I didn't get the damping to work...

* OBJLoader now parses line per line in the same way OBJMTLLoader does.
* No more reusing of the same vertices array.
* Both now create a Object3D when finding a "o" and a Mesh when finding a "g" (or "usemtl").
* I used to like the obj format.