[wsj-responsive-image P="//si.wsj.net/public/resources/images/BN-PB323_0724_E_20160723232648.jpg" J="//si.wsj.net/public/resources/images/BN-PB323_0724_E_20160723232648.jpg" M="//si.wsj.net/public/resources/images/BN-PB323_0724_E_20160723232648.jpg" caption="An image from 'Guardians of the Galaxy: Vol. 2'" credit="Walt Disney" placement="Wrap" suppressEnlarge="false" ignoreresp="E" ] SAN DIEGO — Marvel Studios has popularized the “cinematic universe” model of mashing up its superheroes into the same movie orbit. It helped the studio’s presentation at San Diego Comic-Con on Saturday feel more like a […]