Update question add/edit interface

The question adding/editing interface had some issues:
* It was inconsistent between edit and add operations. Now a consistent view is in place.
* It was not pretty (it had a table view). Now we use a non-table view.
* Not all information was editable in the edit screen. Now that is possible.
* It wasn't possible to dynamically add/remove answers in the question add interface or in the question edit interface. The question edit interface did offer a feature to edit answers but it was pretty clumsy.

There are currently two things that would need to be fixed:
* In order to keep it safe when adding/removing answers, all answers are deleted from the database and then resubmitted. This may cause some overhead when editing a question even if not actually editing answers.
* Scheduling a question (such as the question of the day) is not enabled.
Same as above.