GLOBAL MARKETS-Upbeat earnings, hopes of more ECB stimulus lift mood in Europe

* Sources say ECB considering buying corporate bonds* Earnings results beat expectations in Europe, the U.S.* European shares inch up, euro hits one-week low, yields fallBy Marius ZahariaLONDON, Oct 22 (Reuters) - European shares edged up and the euro hit a one-week low against the dollar on Wednesday, driven by upbeat company earnings results and hopes of corporate bond buying by the European Cen