Quiz

Here is an initial version of this question type for 1.9, which I decided to call multichoiceset / "Multiple Choice Set" for lack of any better ideas. It does share a lot of code with multichoice and making the necessary changes only took a couple hours. The most annoying part was implementing import/export (thus far only for Moodle XML) that's different for non-core questions.

It can't share a whole lot of code with multichoice because of the database table names (at least not without a lot of changes to multichoice), but having it extend multichoice instead of the default question type saves about 175 lines of code. I think I had to change or add about 200 lines of code total, but of course most of the changes were trivial and I probably only had to really think about 50 lines of code for import/export, grading, and the question editing form.

I thought about just adding an option to multichoice, but I think there are too many little differences, like not having the grades as percentages and removing the single answer option and the partially correct feedback field. I think it'd be nicer to have it all as part of multichoice, but I think it might require too many adjustments for people who are used to the current multichoice and don't want this functionality.

I've only tested with 1.9.7. I've tried it out in quizzes and done basic tests for backup/restore and import/export, but nothing exhaustive. It would be great if people who are interested in using this kind of question type could try it out and let me know when they find bugs! If it works okay, I think this could be added to contrib, but I wanted to see if I could find a couple people to test it first.

-Adriane