- Changed so it sets an ordinary matrix. Also removed inversion of position, which broke A LOT of the examples.

WebGLRenderer:
- Using camera.matrixWorldInverse instead of camera.matrixWorld
- Changed frustum check to camera.frustumContains( object );
- Moved cameraInverse * matrixWorld to vertex shader (needs testing!) (note: normals not fixed yet!)

Object3D.addChild:
- Recurses up through hierarchy until reaches scene and adds itself to scene.objects/sounds/lights

Camera:
- Changed inverseMatrix -> matrixWorldInverse