Fix and make file moving better resilient against errors by first copying the files...

Fix and make file moving better resilient against errors by first copying the files, then doing the db updates and finally cleaning up the source.
* FsRepo::cleanupBatch now accepts either pairs, virtual urls and real paths
* Add missing begin() and commit() to LocalFileMoveBatch
* Actually set an error after incrementing failCount because otherwise the status is still good
* Changed some isOk() to isGood() and set ->ok explicitly to false after rollback