Added base class Deck under Models group
Deck is now able to store Cards
Deck now offers a public method to drawRandomCard
Added a new class PlayingCard : Card under Model group
PlayingCard now has rank and suit. Inherited contents method will now return appropriately formatted string.
Improved implementation of contents method. Now unset rank will be represented by ? and ranks higher than 10 are represented by J, Q and K.
Implemented setter and getter methods for suite property. Setter will allow only valid suites and getter will return the suite if it's set, otherwise it'll return ?
Renamed property suite -> suit