- dry run no longer modifies main database and instead modifies a copy
- add scan only option to update database, check CRC, etc
- update command line interface
- update log format
- add verify crc on copy feature, this uses the most recently recorded CRC of the source and compares it to a freshly calculated one of the copy (therefore it could still trigger a copy error if the source file was corrupted between its last CRC recording and an update, eg using an old source with ATTR+ and moving to a fresh dest)