MuteTab per Lijun Wu

Mute tabs by url with pattern matching.
if URL not set, addon is disabled.
if URL matches target URL, the tab will be muted and if not matches, it will be unmuted.

Permissions explained:

Access your data for all websites: This permission is required, because we need access tabs and match URL for all websites.
Access browser tabs: This is necessary, because we need access tabs to mute/unmute tabs.