Ronald Lawrence and Hassan Pore take aim at hip hop’s Bronx creation story, making the case for Grandmaster Flowers, “the original grandmaster” and his colleagues as the originators of hip hop in the parks and nightclubs of Brooklyn and Queens starting in 1968. Lawrence and Pore’s documentary Founding Fathers is the opening film of The Chicago International Hip Hop Film Festival, running Friday and Saturday, Sept. 11-12 at the Portage Theater.