Numpad Utilization 1.7.2

[Brandon Eddy]

I would like to submit this to be added to the official build. I added cases in keyboardButton.h, keyboardButton.cxx, and winGraphicsWindow.cxx to allow unique input from the numpad.

Now accepts:
numpad_1
numpad_2
...
numpad_0
numpad_subtract
numpad_decimal
numpad_divide

One drawback...
This will not allow "shift-numpad_X" calls though. When I set windisplay debug and tested this functionality "keyup: 16" (shift) was always called with any numpad key. This will instead call the alternate inputs listed for the numpad (End, Home, Insert, etc).

If someone else knows how to get around that it would be even more useful.

Attached are the files from the official 1.7.2 that have been altered.