A little over a decade ago, two Boston movie fanatics named Jason Redmond and Adam Roffman ran into each other at the Sundance Film Festival and wondered why there was nothing remotely like that back home. Thanks to them, there now is. With its 10th edition, running from April 25 through May 2 at the Somerville, Brattle, and Coolidge Corner theaters, the Independent Film Festival Boston both hits an important milestone and stands alone as the local film lover’s event that matters.