iTunes integration is considerably more significant on OSX than Windows so how can we make more robust.
1. Build iTunes model in a separate file and copy over when done so if we fail we can use the existing one or if taking a long time because very large we can use existing one.
2. If when edit song found in model but cant find in iTunes best not to add as new file because then end up with duplicate in iTunes, better to do nothing
6. After Fix Songs complete iTunes model has changed, we do update our in memory copy when new songs are added, but dont update when moved and we dont update the actual model.txt file