Add option to do integrity check after copy

[dtenenba]

A user suggests that when initiating a copy, that there be a check box (unchecked by default) which, if checked, will automatically perform an integrity check on the files after the copy is complete. Some users will always want to do this. Or perhaps it could be set in user settings, or at least the default value could be set there, and it could be overridden on a per-copy-job basis in the copy dialog.