Provide option to apply default crop if user doesn't select any

A client had requested a change where they wanted all the default crops to be automatically generated after uploading a file (rather than having to go into the vertical tabs ui and click each crop individually). In case anyone finds this useful, I've added a patch to the module which adds this functionality, plus config to toggle it (default is off).

This issue is necessary to implement queue /automated import with mandatory crop, it could also ease multi-upload process.