Authorities have charged a Gloucester County man with setting three fires last week, including one at an apartment complex and another that destroyed a vacant building that was previously home to a local theater troupe and school. A firefighter suffered a minor injury in one of the incidents. Michael M. Lopez-Medina, 19, of Woodbury, allegedly admitted setting the blazes, according to court documents. The incidents began Feb. 1, when Lopez-Medina used gasoline and matches to set fire to two vehicles in Woodbury, police said. The vehicles were destroyed. The owner of one of the cars told police…