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

Deleting a feedback option will throw an error if it is associated with an mc_option in a finalized exam

Merge branch 'develop' of https://gitlab.kwant-project.org/works-on-my-machine/zesje into fix/mco-feedback-rel

Merge branch 'develop' of ssh://gitlab.kwant-project.org:443/works-on-my-machine/zesje into add-boxes-frontend

Deleting MultipleChoiceOptions

See merge request !13

Changed migrations, changed API since put now no longer requires a feedback_id, changed exams API, changed database script

Added hybrid property to problem, removed direct relation between mc_option and problem, changed API

Draw pdf box

See merge request works-on-my-machine/zesje!6