The cable TV channel home of Jon Stewart’s “The Daily Show” and “The Colbert Report,” Comedy Central has achieved a level of credibility that no longer matches its current logo. The name stuck on the globe with skyscrapers sprouting off the top looks like it was designed in a dorm room. Maybe it was. Once thought of as the basic cable channel featuring adolescent humor, Comedy Central has grown up. Its new logo, designed by The Lab, has too.