When Skylum releases Luminar 4 in the fall, one of its main features will be a new AI-powered sky replacement tool that intelligently masks a new sky into your photos. We already reported on the upcoming feature, but now Skylum has released a sneak peek of the tool in action. The initial announcement came with still photos, and while the results looked pretty impressive, there’s no way to know for sure that they were one-click creations as Skylum promised. This…