Rename columns of quiz_question_instances to match coding guidelines

Grep the code for quiz_question_instances, and ensure that all references to the columns of that table have been updated. (Really, this is a job for the peer reviewer, not the tester.) Read mod/quiz/upgrade.txt and verify that the new bit is intelligible. Verify that the upgrade completes without errors. Create a question, setting the default mark to something distinctive like 13. Add that question to a quiz, verifying that the max mark for the question in the quiz gets set to that default mark. Add some random questions to the quiz, and verify that gives no errors. Edit the max mark for a question, and verify that it gets saved and re-displayed properly. Also verify that the 'Total of marks:' at the top of the page has been updated correctly. Attemt the quiz as a student, and verify that the max mark for each question in the quiz attempt matches what you set on the Edit quiz page. As teacher, view all the quiz reports, and verify that the max mark for each question is correct. Remove that quesion from the quiz. (If you can be bothered, verify that the corresponding quiz_question_instances row has been deleted from the DB.) Delete a quiz with questoins. Verify that all the quiz_question_instances rows for that quiz have been deleted. Find a course or quiz in a Moodle 2.x install (x <= 6). Set the question max marks to distinctive values. Backup that course/quiz, and restore it into your master install. Verify that there are no errors, and the question max marks are transferred accurately. The same, but backing up and restoring a quiz from Moodle 1.9. Create a multianswer (Cloze) question. Add it to one or more quizzes, and attempt those quizzes a few times as students, noting how many times. Then edit thant question and verify that on the editing form it tells you how many times those questions have been used. Create two calculated questions using the same shared datasets. Add them both to various quizzes, and attept those quizzes as students. Re-edit the calculated question, and on the third page of the wizard, veriy that it tells you how many times those questions have been used.