"The perfect guy to pick up the ball." That's how one former P&G executive described A.G. Lafley, Procter & Gamble's new president and cheif executive, who Thursday succeeded ousted leader Durk I. Jager after a rocky year at the helm... Mr. Lafley, born in Keene, N.H., has degrees in history from Hamilton College in Clinton N.Y., and a master of business administration from Harvard Business School. He spent five years in the Navy before joining P&G in 1977.