Read the Tribune's editorial on the election of Barack Obama as president and tell us what you think.On Feb. 12, Americans will celebrate the birthday of their most important and most beloved president. Abraham Lincoln entered the world on that date in 1809 in a cabin near Hodgenville, Ky.His bicentennial would be an important occasion under any circumstances. But it will carry even greater symbolic significance because of something scheduled to happen three weeks earlier: the inauguration of B