GLOBAL MARKETS-Stocks, euro slip as German data, U.S. earnings drag

* Euro dips, European shares subdued after downbeat German Ifo survey * Wall Street lower in midday trading * Amazon.com, Visa down after disappointing results * Russian shares, bonds fall (Updates prices, adds quotes, details on Amazon.com results) By Caroline Valetkevitch NEW YORK, July 25 (Reuters) - U.S. earnings disappointments, including from Amazon.com, and weak German economic data pressured world stock markets on Friday, while the euro clung to an eight-month low a