One More tweak to The Login Screen

I made one more change to the log in screen buttons, I liked the idea of having some variety in the way that the log in code can be made a little more complex without being too complex, if that makes sense ;) I also came across this Keypad on eBay that can easily be used with Arduino and hence ultimately our Knight O.S. Software too. So I added in the A B C D buttons to allow for the use of those character entries also.