MDL-44118 new environment check are all quiz attempts upgraded.

In Moodle 2.1, there was a major DB upgrade relating to questions, and
it was possible to delay some of that upgrade. Now, those DB tables are
changing again, and the time has come to insist that all the updata has
been upgraded (or deleted).
MDL-44118 remove the qeupgradehelper tool

and associated code that was only used by it.
MDL-44118 drop old quiz/question attempt data.

This data should all have been upgraded when moving to Moodle 2.1. It
was only kept as a back-up, and now, after 3 years have past, we can
clean it up.
MDL-43749 DO NOT USE! quiz database upgrade code

Here is the database upgrade code for this issue. However, don't use it
because I have only done the database upgrade part. I have not changed
the code that uses this data, so applying this patch will break your
site.

I have only committed and pushed this for these reasons:
* I wanted an off-site backup.
* If anyone would like to review these changes, then I would love to get
the feedback.
MDL-43749 quiz DB tables. Put install.xml in a more logical order.

All settings tables before all user data.
MDL-43749 document the changes.
MDL-43749 very rought work-in-progress.
More clean-up.
MDL-43749 more elimination of quiz->questions.

So far, this seem to be removing more code than it is adding.

Just mod/quiz/ editlib.php, edit.php and attemptlib.php to go.
MDL-43749 now you can attempt a quiz.

Now, if you had a quiz already before the DB changes, you can attempt
it. Only edit.php and editlib.php to go.

Also, all the unit tests pass, except for editlib_test.php.
MDL-43749 mostly fix the edit quiz page.

I think everything works except:
1. Repaginate
2. Save maxmark for a question.
3. On the order and paging tab, reorder questions
4. On the order and paging tab, move selected to page.
MDL-44251 DB helper to reorder rows without violating a unique index.
MDL-44251 DB helper to reorder rows without violating a unique index.
Merge branch 'MDL-44251' into MDL-43749
fixup! MDL-44251
MDL-43749 complete changes, I hope.
MDL-43098 Update Quiz data layer: added basic slot and section methods
MDL-43089 Create Quiz Edit Renderer

First iteration built on existing data layer. Needs MDL-43098
new data layer to go further

Just implement the course edit view as the edit quiz view. Will later refactor to reflect quiz

Conflicts:

	mod/quiz/edit.php
MDL-43089, MDL-43745 Use new slots data layer in edit renderer

Conflicts:

	mod/quiz/edit.php
MDL-43089, changing the field names in quiz_question_instances table