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

Extra feature detection tests, to know what to load when using library

e.g. 
If no compressed texture support, load regular textures etc
If no float texture support, do multi pass rendering and pack float into rgba
If no dervitives do something else...

GeometryExporter: Changed manual string concatenation with JSON.stringify with prettify. Thanks @sole!
Something tells me that I'll have to refactor (or re-create) SceneExporter...