Add a --verbose flag to commandline utilities

[ssm]

--verbose should make munin emit messages from "info" and up.

The default minimum log level today is "warning".

There's no way to see "notice" and "info" without also getting "debug" (by using the --debug flag)

[sumpfralle]

All components except munin-httpd and munin-cron seem to support --verbose by now.