Camera and Node fixes

OrbitCamera: added getters (public). Setters moved from `protected` to `public
	: Improved API. Instead of using "out" parameters for getters, it returns a `kmVec3`
 	: Setters receives `kmVec3` as well. Old API is still supported

Node: `setAdditionalTransform` doesn't get `dirty` on the next frame.
	Instead, once the additional transform is set, in order to remove it the user needs to pass
	the identity matrix