Randy Jackson is not the kind of person who can sit back and wait for others to take action to improve the Katahdin region. That’s why the former Millinocket town councilor last year bought a long-vacant downtown building. His dream was to bring some culture to the former mill town by converting the property into a 48-seat performance space. Called the Boreal Theater, it held its opening event last month featuring a small jazz band and a sold-out crowd.