Added Vector3.applyEuler() and Vector3.applyAxisAngle

We now have all four rotation representations represented is Vector3.apply*();

Caveat: I had trouble getting this to build, as I needed to declare within `Vector3.js` the following:

    THREE.Vector3.__q1 = new THREE.Quaternion();

But due to the build order, it was forward-referencing `Quaternion`. Not good.., so I declared it in `Quaternion.js`, instead. I know we don't want to do that. This needs to be fixed, somehow.

I think the solution is to change the build order, but that can be a Catch-22...

I'd appreciate help with this one. :-)