Formatting changes, new methods on MDMPersistenceController.

Some small changes to use literals, used `containsObject:` rather than `indexOfObject:` added two new methods. I think we might have to fight about the space within each method, but I will roll with it for now. Other than these few things, everything looks good.

However, I do not like have the example using CocoaPods in the way that it does. Makes it harder to make changes to the project since the source files are not really accessible through the example project.

I am up for debate on the added methods. I added them earlier in the week for doing GamePlan, but maybe they are not appropriate here? Let me know what you think.