Ability to automatically add a student to a group if they register for a certain class.

It would be nice to be able to assign a certain student group to a class when we create it, and have the system automatically add everyone who registers for that class to the group.

Benefits:

• If dancers in a specific class get a special discount on a different class, having the student automatically added to the group would allow the discount to show up immediately. This would also allow the system to be set so that tuition is charged immediately instead of having to do it manually to make sure the discounts are applied before the charge is posted.

• The same idea applies to if group emails are being sent out - students would be less likely to miss out on information going to a special group of dancers simply because someone missed adding them to the group after they registered.