iTunes customers can now buy and rent films in high definition. If you thought this feature was already available, let us clear up the confusion. High-definition content was first announced at Macworld Expo 2008 in concert with the Apple TV Take Two update and the introduction of movie rentals. At the time, only rentals were available in high-definition, and only Apple TV owners could rent those HD titles. The HD line-up expanded in September when Apple added HD television episodes to the store, but you couldn’t