This makes the student registration confirmation email prettier, copying most of the changes from #3706. The receipt setting now modifies the pretext of the email (which is now an HTML email). The rest of the email includes various bits of information, including the student's schedule. Because the email now includes the schedule, I've changed the behavior of the confirmation button to now always send a new copy of confirmation email.
This makes the student registration confirmation email prettier, copying most of the changes from #3706. The receipt setting now modifies the pretext of the email (which is now an HTML email). The rest of the email includes various bits of information, including the student's schedule. Because the email now includes the schedule, I've changed the behavior of the confirmation button to now always send a new copy of confirmation email.
Fixes #3753.