added a throw if no path for check_file_existence_on_disc(); removed the disconnect from update_stats_from_disc() so we can do stuff with files within transactions
added a throw if no path for check_file_existence_on_disc(); removed the disconnect from update_stats_from_disc() so we can do stuff with files within transactions

wtsi-hgi/vr-pipe,wtsi-hgi/vr-pipe