student enrollments. We no longer need to parse the course key into an
opaque key since the opaque key class can already handle strings and the
parsing happens there. We also need to specify which course enrollment
are we editing or else the reference is lost when saving the edits.
unlock student accounts that have been locked out for excessive login
failures. This change will allow to quickly unlock student accounts when
time is of the essence (e.g. Timed exams).
* uses openedx waffle_utils instead of straight waffle
* adds student.STUDENT_WAFFLE_NAMESPACE
* improves comment
Also changed the waffle switch to use _ instead of . to respect current conventions.
