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