jse3d v2.2

jse3d v2.2
Note: Vector arithmetic coming in a future update.

Changes:
-Renames Point3D to Vector3
-Adds methods to get a vector's magnitude, square magnitude, and normal
-Vector instance variables are now protected, and use getters and setters
-Scaling is now possible on vectors and Object3Ds, with a specified center point
-Classes that represent 3D entities or that represent properties of 3D entities now override Object.equals(Object)
-In classes where having this method makes sense, Object.toString() is overridden