Leaders thrived Friday as the market ended the week in fine form. That's why they're called leaders. Many of the best-rated stocks already have flown beyond reach of their breakout, add-on or rebound buy points. But fashion house Michael Kors (KORS) is in the 12th week of a base-building effort. So far a cup is emerging. The right side came within 2% of the left side Friday, as the stock logged its fifth straight daily gain. For now the buy point