Using step dispenser in window display
Class IStepperRegistrar is an interface on which steppers can suscribe to receive steps, Mover needs it
Adding GL to the libs used in gui Makefile
Drawables are used to display GL objects, drawer draw them all
Adaptating WindowDisplay and main code to display a simple moving toward a position
Adding a empty line at the end of MockChronometer
Fixing a bug where vector computing from 2 points ended with reversed direction, added test
Cross is now moving from 600, 400