Two fixes for bookings and instructor pay setup.
- When you book a group class that needs a court, bed or other equipment and the last unit is taken while you are booking, the booking now tells you the selected equipment is no longer available and lets you pick again, instead of saying there are not enough spots.
- Seat availability and equipment availability are now reported separately, so a full class and a fully booked piece of equipment no longer look like the same problem.
- Changing the name or rules of an instructor pay formula no longer removes instructors who were assigned to it but are archived or no longer marked as instructors - everyone assigned stays assigned.
