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

Change the docs to reflect the true default of the fog parameter in MeshBasicMaterial.

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

This is the implementation of buffergeometry with lines: f53b2753 in webglrenderer2

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.

update math constructors to not copy when provided explicit initial values per @mrdoob: https://github.com/mrdoob/three.js/pull/2902#issuecomment-11999928

Frustum bug fix: clone and constructor should be real copies.  Fix bug in unit test to catch this in the future.

Conflicts:
	test/unit/unittests_sources.html