Refactor/Add: GameState

GameState becomes base class. Game's states now defined in
JeopGameState. Also added a new state, DELAY, and implemented its
transition rules in main.
Add feature: Delay

Upon answering correctly, there is now a short delay between drawing the
updated score and redrawing the game board, so the eye can be drawn to
the score change.
Minor fix: controller

Switched this check around for better logic and clearer flow