Five years ago, Mylan (MYL) became the third-largest generic-drug company in the world, catapulted by two acquisitions totaling around $7 billion. But in late October, Watson Pharmaceuticals (WPI) overtook Mylan when it bought Swiss partner Actavis in a deal valued at $5.9 billion. Mylan dropped to No. 4. So Israel's Teva Pharmaceuticals (TEVA) and the Swiss firm Novartis (NVS) remain the top two generic-drug firms worldwide. But Mylan may get