Lecture 5: Demo - Game results by "end" date instead of "start" date
Assignment 2: Add tab bar controller for the Set game
Assignment 2: Layout 24 buttons for the Set game
Assignment 2: Add classes for Set cards and deck
Assignment 2: Define card via init instead of properties

Using an initialiser makes sure that the card properties can't change 
"on the fly". That would be cheating :)
Minor comment tweak