Feature Request: Toggle functionality to work only in instances.

[Ghosthree3]

My only reason for grabbing this helpful plugin was to avoid the risk of being dropped from instances with door bosses whenever the group decides to take a long/extended break. It's not a deal breaker, but having the plugin always active stops me from getting the afk status symbol in non-instanced areas, which could potentially mislead others. A simple switch, "Enable only in instances?", could be of benefit here.