Lecture 6: Multiple MVCs

The code for this was touched up a bit after lecture to build properly on 64-bit systems (index variable in characterWithAttribute: and the stringWithFormat: calls). We'll endeavor to make the demo code correct for 64-bit systems, but occasionally we'll fall down on the job (apologies in advance for that) because we always build for the 3.5-inch (thus, non-64-bit) iPhone for screen real estate reasons.