Apple has started sending out free iTunes Movie Rental codes to select iTunes users, according to a new report. Citing an email received by a reader, 9 to 5 Mac reports that the included code is good for one rental from iTunes’ library of over 8,500 movies, and that the distribution of the codes seems to be random. Most likely, Apple is attempting to use the promotion to raise awareness of Movie Rentals on the iTunes Store, perhaps hoping to…