Please add an option to suppress warnings.

Typically, clamscan runs for many hours, and I only want to see output for infected files.  `sudo clamscan --quiet -ir /` doesn't do that - I end up with pages of warnings, more than the buffer in my shell.
Yes, I can output to a file, or pipe, and then filter, but it seems natural to have an option flag for it, or a verbosity setting.

Thanks for an otherwise great program, though!