manage questions workflow

this patch aims to make it much easier to add questions to a quiz.

1. when on the "manage questions" tab, the fieldsets are re-ordered so "add new" comes first, followed by the questions already assigned to this quiz, and lastly the table of all questions available. This makes it easier to see what you've already entered, and links to add new are at the top.

2. both when adding a new question or editing an existing one, the quiz id is passed along. After you're done adding/editing, you will be returned to this page. If you created a new question, it will automatically be added to this quiz with status ALWAYS.

It doesn't automatically update the number of questions in the quiz (this will happen when you save the quiz anyway). It would be fairly easy to add this, but it could lead to unexpected changes if you have random questions...