iTunes Controller

Based on a suggestion and code from Robin Sheat's "modifications":https://code.launchpad.net/~eythian/+junk/itunescon to itunescon, it would be a good idea to abstract the ITPlaylist process (where the getPlaylist etc functionality return the actual playlist kind so it can be casted to its correct form). Jacob does not provide any means for this automatically, which is why it is necessary to perform the process of checking the type manually. The suggestion would be to replace the code that performs this method many times throughout the library with a single static method in the ITPlaylist class that could perform this.