Created newQuestionClass

-added questionType to the Prefix.pch file
-created new QuestionClass
-gave the question class properties for MC questions, fill in the blank
questions, and image type questions
-initiated an array in the Question model
-added dummy questions to the array in the model
-in storyboard added user interface elements for the different question
types
-exposed these elements to the viewController.h file as properties for
each question type
-viewController.h give properties for the model and the question so
they can be got into the viewController.m file and manipulated
-helper method used to keep all user interface elements hidden when
view loads at first