Added the declaration of all public methods and all properties to all our classes, per our Alpha UML Class Diagram. Also added private methods cellPressedAtRow:col: to the LevelViewController and GridView because they are architecturally important.
Added stub implementations for all public methods. Each method has a "TODO" comment in it. Also added #pragma marks for "Public methods" and "Private methods".
Merge pull request #3 from zsweedyk/interface-setup

Interface setup