#279 In-place verification (check) for local backup files

[Fernando Lozano]

It looks like Areca allways makes copies of backup archives before checking then. Even when the files are stored on a local disk (instead of a FTP/SFTP server). My backup sets are large, it would be nice being able to check then without this copying overhead -- and without the need to have disk space for the copy.

When files are on a remote SFTP server, it should be possible to download contents incrementally and check then on the fly, instead of making a local copy, so the source machine does not needs so much disk space.