Add differential downloads
Add differential delete
Refactor differential upload
Better counting of objects needing processing. Comments
Fix object url in download log
Improved log
Use getObjectURL where possible
Update docs on differential processing
Add docs about dest. Fix write/search paths for download/delete
Remove verbose log
Add tests. Fix differential delete
Precisions on the accuracy of the debug mode
Fix delete task when no file to delete in differential mode
Comment + style fix
Update mock-aws-s3