LONDON, Nov 13 (Reuters) - London's Metropolitan Police have dropped an investigation into a complaint made against referee Mark Clattenburg for alleged inappropriate language towards a Chelsea player last month. The European champions lodged a complaint with the FA over language allegedly directed at their Nigeria midfielder John Obi Mikel by Clattenburg during the home Premier League defeat by Manchester United on Oct. 28. That prompted the Society of Black Lawyers to lodge a written complaint with the police. ... More...