By Caroline Jacobs and Gilles Guillaume PARIS (Reuters) - French car maker PSA Peugeot Citroen (PEUP.PA) posted a 1.5 percent drop in car sales in 2011 as expansion in emerging markets failed to offset a decline in its market share in crisis-hit Europe. Europe's second-biggest car maker after Germany's Volkswagen (VOWG_p.DE) said it sold 3.5 million cars ...