Podfile.lock (couldn't sync branch without committing this).
Added NSCoding interface and (unimplemented) interface methods
Added NSCoding implementation.
Added NSCoding implementation.
Added NSCoding implementation.
Added NSCoding implementation.
Added NSCoding implementation.
Added NSCoding implementation.
Added manager for PersistentStore
Weird line break removed.
Updated classes related to Persistent Store
Updated comments.
Small change in project structure
Updates regarding PersistentStore
Completed implementation of the Persistent Store

For now, questions retrieved from the backend are persisted. When
questions are retrieved from the backend and the request fails, the
persisted (cached) questions are returned instead.
Merge pull request #40 from jorisvervuurt/master

Completed implementation of the Persistent Store (for questions).