By TOM SHANAHAN Martin Luther King Jr. visited Michigan State University’s campus 56 years ago today at the invitation of president John Hannah, African-American professor Dr. Robert Green and Michigan State's student government. MLK spoke to a full house of 4,000 that greeted him with a standing ovation on Feb. 11, 1965 at the MSU Auditorium. Among the crowd was Gene Washington, a passenger aboard Michigan State coach Duffy Daugherty's 1960s Underground Railroad teams that led college football…