quiz 7.x-5.0-alpha2

Database updates included.

Please make sure to backup your database and run update.php

In this release:

#2278691: Date API to make calendar
#2268045: How to add image in the question?
#2281493: Merge admin and user results
#2282653: Quiz question universal class for CSS
#2278083: Random Order and Quiz Page don't play well together.
(related issues with random questions in pages)
#2269219: Revamp feedback permissions
#2287915: Missing text format: 2.
#2299233: Multiple choice question type can be skipped even when "allow skipping" is disabled
#2291279: Use entity save for Quiz result, quiz result answer, and quiz node defaults
#2301309: Very slow when grading
#2313769: Commented function in module file
#2314093: Database update SQL error

Misc:
Better quiz stats charts (still WIP)
Various access changes
Fixed issue with categorized random question quizzes losing a question
Added a warning in certain cases for categorized random question quizzes
Fixed issue where "leave blank" skipped a question