add api course_student_practice_report
Changed return type to array.
Enabled multiple choice.
Pulled Nirmal’s changes.
Merge remote-tracking branch 'origin/back-end-working' into back-end-working
Improved performance by giving permissions hints for Entry.copy_for_user().
Add more unit tests
DB changes and mode setup for practice related changes.
more unit tests for course
Minor optimizations.
Testing APIs!