This adds Vector3.getRotationFromQuaternion and changes Object3D.applyMatrix to use Matrix4.decompose.

Also added SceneUtils.attach / detach and cleaned up unused vector parameter in Geometry.applyMatrix.

Renamed Vector3.setRotationFromMatrix() to Vector3.getRotationFromMatrix().
Added Vector3.getScaleFromMatrix().

Still not done.

No markup learning, no compilation process. Just simple HTML.
Still, working on it.

As usual, it's up to caller to cache the value if it's not used right away.

Had to use Matrix4's internal matrix to avoid circular cross-dependency between Vector3 and Matrix4 (added extra internal matrix m3 for this not used anywhere in Matrix4 itself to minimize chances of messing up something).

Added Vector3.absoluteToRelative and Vector3.relativeToAbsolute. Thanks to @G3z for the initial suggestion. Thanks to @em for the naming hint. Fixes #1043.