Point to different MP3 URLs

Using HypeMachine's own API, we can actually get either a direct third-party MP3 URL resulting in better naming when saving an MP3 (unless, of course, the MP3 is being pulled from SoundCloud).

For example:
With "[Frank Ocean - Eyes Like Sky](http://hypem.com/track/1tpmq/Frank+Ocean+-+Eyes+Like+Sky)", instead of pointing to [hypem's play service](http://hypem.com/serve/play/1tpmq/859e1aa6b765b09bc55011a3ffa2443c.mp3), it points directly to the blog at: http://www.chromemusic.de/wp-content/uploads/2013/02/Frank-Ocean-Eyes-Like-Sky.mp3 by requesting the [source](http://hypem.com/serve/source/1tpmq/859e1aa6b765b09bc55011a3ffa2443c) and parsing the returned JSON data.

The only con is that an HTTP request *does* have to be made for each song.