Added Game Controller Object

Refactored the code to include the Game Controller Object in preparation
for implementing the game logic.

The Game Controller will track the game state variables, validate player
actions, and control the game flow.
Partial Game Logic Added

Added Game logic so that only a card with higher value than top pile
card can be played unless it is a special card.

No logic for special cards has been added.

Minor graphics update to indicate when buttons are playable.
Game Logic Rev 1

First attempt at Game Logic. Current status is horribly buggy.

Added logic for special card functions and different interactions with
game buttons. Will revise as soon as possible.
Minor Bug Fix - State: Unstable

Fixed a bug where game would allow you to draw a card instead of pick
the pile when no valid move existed.

Fixed a bug where active player would not draw up to three after playing
a ten card.

Fixed a bug where validMoveExists() function was searching wrong card
container causing and error to be thrown.

Added cardVal() function to card object to instantly query card's
strength value (i.e. 2, 10, J, Q, A, etc).