Once upon a less digital time, there existed the art of the mixtape: a tedious labor of love that required timing, taste and a penchant for musical progression. No longer in this iTunes-era, where personally curated song collections that once served as the background to our lives can now be automated by our dear friends in Cupertino. And, based on a patent application filed back in August of 2010, those Apple-made robo-playlists could get even smarter and slicker, with your perennially hip, millennial compadres being none the wiser. Accordi