This allows the reviewer to track students across different views in the frontend or map an entry in the FeedbackHistory list to a natural person

Tutors and reviewers can now add comments to individual lines of the provided solution. The comments are short polled.

also some quality of life ui improvements

fixes #137

For now, every occurence of "student/s" that is visible to the user has been renamed to "participant". We should however think about how we adress the naming in the future.

also removed one passible cause for memory leak. Feedback was unnecesarily stored in the store under state.feedback

Use postgres:9.6 is ci

Nearly completed typing the whole store!