Crash on exit due to Mp3Tunes service

[Nikolaj Hald Nielsen]

> The crash on exit has now mutated into a crash on startup :( You
> really need to rethink some things in the Mp3Tunes service, Casey.

I think that phrasing is putting it a bit more "on edge" then is
really needed. For me it also crashes on startup with the auto
synching enabled. However, I think the overall architecture is sound
while the intricacies of using a g_main_loop inside of a QThread needs
some work.

- Nikolaj