STOCKHOLM (Reuters) - Centre-right opposition leader Fredrik Reinfeldt, who has pledged to cut taxes and trim the welfare state, formally became Sweden's new prime minister on Thursday after winning a vote in parliament.Reinfeldt got 175 votes in his favor and 169 against in the 349-seat parliament, had been expected after he led a four-party alliance to victory in a September 17 election.Reinfeldt, who leads the Moderate Party, will on Friday formally lay out his government's plans for the next four years and present his cabinet. He will launch a budget on October 16. The coalition includes the Folk Liberal...