CRANSTON, R.I. — Mayor Allan W. Fung announced Friday that the city has beaten back a court challenge to a deal that he made to temporarily trim retirement benefits for some police officers and firefighters in order to maintain the solvency of their retirement fund.In a deal that he made more than three years ago, Fung persuaded the police and fire labor unions and the majority of participants in a closed city pension system to accept substantial limits on their annual [...]