Mute YouTube ads by Ilya Komlev

Mutes any <a href="https://prod.outgoing.prod.webservices.mozgcp.net/v1/878cc656c62a85726943ba46ea8d584d2cbb306e2464cf7d7faf95de12c9baae/http%3A//www.youtube.com" rel="nofollow">www.youtube.com</a> tab when it detects video ads on it. Unmutes the tab when the ads are gone. Backs out on tabs where you manually change the muted state of the tab.