Apple will demonstrate a new version of the Apple TV operating system at its upcoming Worldwide Developers Conference, according to a new report. Citing a “trusted source,” BGR claims that the new OS is more “feature-complete” than the current OS that runs on the set-top box, and says that it’s the same version that will run on Apple’s as-yet-unannounced HDTV set. The report goes on to claim that Apple is actively…