Changed commented out code back, changed the way errors are printed, added temporary fix for box check, feedback description should be the label of the mc_option if it is present

Merge branch 'combinatory-fixes' of https://gitlab.kwant-project.org/works-on-my-machine/zesje into feature/pre-grading

adds a bit of padding to the x and y coordinates to allign the generation with the  placeholder checkbox

Fix relation between MultipleChoiceOption and FeedbackOption

See merge request !12