support iOS 7 can save new candidates

I re-created the project because for some reason it would not work for
me. No worries - I think something went wrong in Xcode, not our code.

The app will now run on iOS 7+ devices.

I fixed the CoreData stuff to assign new GUIDs for the candidateID
field. Also, You can now create, edit, save and delete Candidates, so
all the CRUD functions are done! Yay!

Next, please make the deserializer for the Right-hand view
(DetailViewController) to light up the positions and skills buttons
based on the string from the database. I will start work on persisting
the DB so that we all use the same DB going forward (right now it’s
just local and every fresh install creates a new, not shared DB).