Minor code formatting.
(1)-Mapped all inputs for my gamepad, for both 'D' and 'X' input types.  (2)-Moved Input class to globals.  (3)-Added INPUT1 and INPUT2 to global namespace, access via GL.INPUT1 and GL.INPUT2.  (4)-Tweaked Player class appropriately to handle changes to input.
Changes to input handling.  ESC from HelpPage or OptionsPage or GameLoop returns user to StartMenu; ESC from StartMenu exits the game entirely.
Significant changes made to Input class and overall input handling.   Directional pad now works on my (Brian) gamepad.  Select button on gamepad now has same functionality as ESC key; start button has same functionality as Enter key.
Changed input handling so that the only input that can be received during a paused game is the input to un-pause the game (i.e. enter key or start button).