Enable adding & removing points while retaining old annotations

[beijbom]

https://groups.google.com/d/msg/coralnet-users/iQnW_Ftln6Y/plp_b2OCAgAJ

From user:

"Until now, we have uploaded many photos and defined the number of points to be 25 per photo. Now, we want to switch to 50 or a 100, can you help us do it retroactively for photos we already analyzed?"

The suggestion is currently not possible since any change in the number of points will remove all points (and thus annotations) and then generate new ones. This was done to keep things as simple as possible, but given some time we should be able to fix it. If you decrease the nbr points, we can remove them randomly, and if you add more, we can add points while keeping the old ones. For the stratified systems, this becomes more complicated, so we may have to restrict it to the simple random points generation schemes.