refactoring for the new QuizViewImpl class which holds the String view,
(replacing the String view formerly in QuizControllerImpl.)
new Class/Interface QuizView
SetUpClient now works. (See previous commit for detail). 
PlayerClient does not, because the code to pass the controller from
setUpServer does not seem to work. I guess persistence would require
read/write to file. (I don't know if I should spend even more time on
Quiz coursework, I have all 3 OODP coursework still to complete as
well!)