By Gavin Jones ROME (Reuters) – Italian Prime Minister Mario Draghi is likely to have a hard time controlling his coalition, politicians and analysts warn, after relations within and among the ruling parties worsened over this week’s election of a new head of state. Outgoing 80-year-old President Sergio Mattarella was re-elected for a second term on Saturday, with party chiefs asking him to carry on after seven rounds of fruitless, often fraught voting in parliament to choose a successor. With elections in the euro zone’s third largest economy little over a year away, Draghi now has to lead hi…