Created content folder and text files to hold story lines
sets levelAccomplished instance var to false at start of new level
Created levels class

Levels holds all of the levels and a graph of all of the levels. An
instance of Levels is passed into the Game panel of the GUI.
Oh man so many changes, okay, hm. Well the GUI works now!

GUI game panel works with this commit! Takes in instance of CodeCracker
and instance of Levels and allows user to change levels, etc. A lot of
other things too.