QUIZ module done, Multifile Upload POC, Tracks Screen

- TABLES CREATED: lectures, track_rating, quiz, quiz_questions

- MODELS CREATED: track, lecture, track_rating, quiz, quiz_question
- MODELS UPDATED: course

- CONTR. CREATED:
- CONTR. UPDATED: courses

- SCREENS ADDED : track-in-progress, track-explore, quiz-add,
quiz-result, new-track-wizard, course-playback
- SCREENS UPDATED: quiz, tracks

- vitdb.sql updated
upload directory is now clean, ready for next commit

upload directory is now clean, ready for next commit