LONDON (Reuters) - World shares and gold rallied while the dollar fell on Wednesday after President Barack Obama was re-elected for a second term, signaling no dramatic shift in U.S. economic policy. Gains in Europe's main stock markets were expected to be limited, however, as attention switches to Greece where parliament votes late in the day on an austerity package needed to secure a fresh injection of EU/IMF aid and avert bankruptcy. "The fact the election is over is obviously positive for the market. ...