More collision objects

I need some objects for collision detection. I implemented only the features, like intersection tests and other methods, that I need. But I hope that others users of the library add the features that they are missing. I will probably later add some more features, but at the moment I don't need more.

Summary:

* AabbN
  * More intersection tests
      * Point
      * Triangle
  * Renamed contains and intersectsWith to containsAabb and intersectsWithAabb to allow a better naming scheme. This is a breaking change =/ not sure about it.
* Sphere
  * Sphere 
  * Point
* Ray
  * at method
  * intersectsWithSphere
  * intersectsWithTriangle
* Traingle
* VectorN
  * distanceTo / distanceToSquared