Wall Street Journal: This Friday, Comcast’s Universal Pictures releases the big-budget “Furious 7” — the very embodiment of a “summer popcorn movie.” Never mind that it is opening in early spring. As profit pressures force studios to make more “tentpole” films, and less of everything else, the May-August corridor has become so crowded that film execs say they have no choice but to start pushing the “summer” season back earlier.