By Dave Snelling Fancy watching premium Sky channels and Netflix for free during April? Sky is offering exactly that thanks to a money-saving promotion on its Sky Stream device. This diddy set-top box sits neatly under your TV and whizzes live and on-demand content to the big screen via your broadband. That means there’s no fussy installation needed and no need to have a dish stuck to your walls. Right now, those signing up for Sky Stream will get this box free for an entire month with Netflix included as part of the bundle along with paid-for channels such as Sky Atlantic, Sky Documentaries, …