NEW YORK (AP) - During a tumultuous time in morning television, the competition between the “Today” show and “Good Morning America” can’t get any tighter.The shows finished in a dead heat in the Nielsen ratings last week, both averaging 4.604 million viewers. It was the fifth time in 12 weeks that ABC's “Good Morning America” had claimed victory, or a slice of victory, since snapping a “Today” winning streak that had stretched back to 1995.NBC’s “Today” actually won Monday, Tuesday, Wednesday and Thursday in the ratings last week.But on Friday, the day after Ann Curry made her tearful farewell from “Today”, the NBC show was crushed by a 670,000-viewer margin.