UPDATE 3-Fed tells JPMorgan, Goldman to improve capital plans

* Lets JPMorgan, Goldman proceed with plans * Fed rejects capital plans by BB&T and Ally * Other major banks can proceed with dividends, buybacks * Shares of JPMorgan, Goldman and BB&T fall after hours By Emily Stephenson and Rick Rothacker March 14 (Reuters) - In a blow to two major Wall Street banks, the Federal Reserve told Goldman Sachs Group Inc and JPMorgan Chase & Co that they must fix flaws in how they determine capital payouts to shareholders, but still approved t