Add ./user_practice.php and ./user_practice_response.php support.
Added mock test creation page and unit tests
Implemented annotation-related functionalities.
Implemented course workflows for students and instructors.
Refactored code.
Removed extraneous stubs.
Merge remote-tracking branch 'origin/master' into back-end-working
Merged in Nirmal’s changes, which had been pushed to master instead.
Implemented getters for students and instructors.
Minor changes.
Corrected an error introduced by an earlier commit.
Implemented workflows for course students and instructors.
Course workflows for students and instructors work (viz., enumerating, adding, removing).