This interface is to be used in conjunction with the Upload class. Create a concrete class
that implements this interface and pass it to method Upload.setDbCleanInstance(DbClean dbc).
If you do not set this instance, Upload will perform its own cleanup routine. That routine may
or may not be appropriate for your circumstances. If the latter is true, create a class using this interface that performs
the appropriate actions to take to clean up your database and any thing else you deem appropriate.
The cleanup routine in Upload will first determine what records in your database table are no longer being
referenced and will pass to your clean(...) method the ids of those records.