Some work on the JavaScript, added first CSS transitions
Changed smo_user::get_learn_periods, added html skeleton for /~/learn-periods
Merge commit '9ba55f2742f460f7d0e8ce17dec19debcca40325'
Allowing the grade_system_id in learn_period to be unset / NULL
Merge commit '47f82ed1a6ed921680e0ddedfba0a6f9e1eb3911'