Vectrex joystick now fully supported and tested!

We finally have a fully functional firmware for Vectrex joyscticks! Special thanks to our community collaborator from France, Eric Andreani. Many issues were fixed. This joystick is a totaly different beast because it is entirely analog on different pins than other joysticks and paddles. All 4 buttons with dual axes are seen by the host computer. Time to fire up your Vectrex emulator or try it on your favorite game!