Merge the code that handle external web-services with the main branch

- Created QwizzleStore object that handle network requests for every
object in the app
- Created Connection object that handle routine network request for the
QwizzleStore object
- Created JSONSerializable protocol for object that will handle JSON
data
- Created QWZQwizzle that wrap both QWZQuizSet and QWZAnsweredQuizSet
together and also handle and parse JSON data received from the external
web service
- Added a refresh button to test the connectivity