Listen on D-Bus events rather than polling

[sewnie]

rescrobbled polls every 500ms. This design choice would make sense in a setting where listening and recieving events asynchronously is not available, but D-Bus natively provides this feature, removing the needing for polling.

[InputUsername]

I agree that this would be the better approach. I have tried it in the past but IIRC there were some issues that meant it didn't work too well. I'm open to using that approach though, it may also resolve other issues.