10 years ago (2. update 9 years ago)
Actually this should be handled similar to deleted persons.
If the tasks have to be deleted, because it would be too slow to check for the state of the project for each query of a task. For this we would need a revert tag in the item_changes table, which would be a good idea anyways. This tag would group all changes of an complex operation with a GUID (a random id).