show all submissions of mixed type in the submissions tab.
view training submission & grading.
refactor current_uc to curr_user_course. current_uc was a terrible name
show number of new submissions in the sidebar for lecturer.
in viewing training submissions, students should not see questions they have not attempted, or which answers are correct in the choices.
change user_id to user_course_id in activities and notification to easily refer to the users in the context of the course.
fix quiz stuff & have a simple user profile page.
improve achievement list minimally.
add leaderboard.