With Greggman's changes

Folded in this code
https://github.com/greggman/three.js/commit/fde9f9917d6d8381f06bf22cdff766029d1761be
Also added documentation.
Merge branch 'master' of https://github.com/erich666/three.js into dev
Improvements to examples viewer.
Fixed some more examples.
Examples still broken: webgl_geometry_subdivision, webgl_materials_video