Here is a Hollywood maths problem for you: feature-film making as we know it is well over 100 years old. Members of Generation Z, those born between 1995 and 2012, are now between 10 and 27. How long will it take the entertainment industry to bridge the gap? For a number of summer movies, the answer is not just “not long” – it is “now”. Bodies Bodies Bodies , directed by Halina Reijn from a screenplay by Sarah DeLappe; Sharp Stick , written and directed by Lena Dunham; and Not Okay , written and directed by Quinn Shephard, are all…