By Matthias Rieker Of DOW JONES NEWSWIRES NEW YORK (Dow Jones)–In banking circles, convergence talk is back.Mergers between investment banks and commercial banks had become rare untilJPMorgan Chase & Co. (JPM) bought Bear Stearns, but falling profits and tougherfunding have hurt Lehman Brothers Holdings Inc. (LEH), Morgan Stanley (MS),Merrill Lynch & [...]