ios demo app: QuizApp_grabFromServer

Grabs quiz(es) from server and shows each question to users.  Users can
quit in the middle of quizes and when app relaunches, user starts from
same location.  At the end of quiz(es) users get a score and then
starts over.  Identical to QuizApp except that QuizApp_grabFromServer
gets the quiz info from a server and not a locally stored text file.