quiz 6.x-3.4

This release contains minor bug fixes since 3.3.

Fix #597774: array_pop() error messages.
Fix #614020: Feedback page not displaying answers
Fix #586584: Fatal error: Class 'ShortAnswerQuestion' not found
Fix #632154: Question missing node format
Fix #536116: Multichoice module causes string of access_denied() in cron, search output and node preview
Fix #662478: The results at the end of the page displays n/a
Fix #344193: Correct answer not seen when user views any result under 'My Results'
Fix #365409: Input filters for question results
Fix #530214: New question types not found in quiz_question.module
Fix #517602: deprecated use of form array in matching administration page
Fix #344926: unable to take quiz when integrated with gradebook module