lab 12: Objective C Tutorial: memory management and free

[aaronbloomfield]

From aaronbloomfield#134:

free isn't a method in NSObject (perhaps it was at the time of writing and it isn't any more). I'm not too familiar with Objective C memory management (other than knowing it uses reference counting), but I believe that the proper way to deallocate an object created with [SomeObject new] is with the release keyword (e.g., [SomeObject release]).