[KLMB/CAMERA/CAMERA]: camera is now able to track objects automatically.
[KLMB/TRANSFORMATION_TREE]: transformations are now effective only if the parent has changed, and it has now both a 'local' and 'global' transofrm object (world = parent.world + local). Matrices are only used at the end of the chain: to transform a final object. (they are no more used into intermediate stages (we have quaternions :) ).
[KLMB/SAMPLE/TEST]: both camera tracks an object, that is moving. Modified to follow the changes in transform_tree