Fix for issue 523.  Numeric keypad constants in docs don't match key.py.
Fix for issue 523.  Numeric keypad constants in docs don't match key.py.

infowantstobeseen/pyglet-darwincore,infowantstobeseen/pyglet-darwincore,infowantstobeseen/pyglet-darwincore,infowantstobeseen/pyglet-darwincore,infowantstobeseen/pyglet-darwincore