Updating Italian translation

Thanks to:

dott. Alessandro Mignogna
Web & Mobile Developer, System Integrator
Asernet Srl
www.asernet.it

Signed-off-by: Elliot Condon <e@elliotcondon.com>
Included message about terms and conditions relating to add-ons in plugins

Signed-off-by: Elliot Condon <e@elliotcondon.com>