users are able to reset the game

Assignment 1, question 4. The redeal function set the self.game pointer
to NIL and reset the flip counter to 0.
Modified to match N different cards

- There are only two matching modes: TWO_CARDS_MATCHING and
THREE_CARD_MATCHING
Added a property to add a Card's back image
Changed the match function to match multiple cards

The score has been modified.
Finished Assignment 1