Wednesday, October 21, 2015 was “Back to the Future Day.” If you’ve not seen the movies, in “Back to the Future Part II,” Marty McFly and Doc Brown travel to this date to save his future children, who weren’t born yet in the film’s present, which was 1985, from a horrific future. Confusing. Yes, but a lot of fun. It’s also fun to look at all of the events and inventions that film, directed by Robert Zemeckis, playfully predicted would be coming....