1) Used a Blank Piece instead of checking null button (which might cause
the button not to work) inside of the GameGUI. Updated all code
associated with this. I tested the blank button and I know it works.

2) Consolidated a lot of the code in both of the GUIs & fixed a couple
bugs where the game buttons weren't in the correct spot.
 
3) Fixed the bug in the How To Menu that caused the slides to be out of
order (Updated in Menu & Game How To).

The GUIs SHOULD be completely done (except for the game win menu) at
this point.. they probably aren't, but we can and should start testing
code ASAP.