PG | 1h 48min | Drama, Comedy | 1967 Stanley Kramer’s “Guess Who’s Coming To Dinner” is all of 108 minutes, but packed with truth and insight that echoes beyond its genre, its generation, and its geography. Young Joanna or Joey (Katharine Houghton) tells her parents, Christina (Katharine Hepburn) and Matt (Spencer Tracy), of her…