RUFISQUE, Senegal — Members of a 200-strong audience struggle to hold back tears as the credits roll on the film “Io Capitano” in a small auditorium in the outskirts of Senegal’s capital Dakar. The crowd has spent two hours following a pair of Senegalese teenagers as they risk their lives to reach Europe, facing a gruelling journey across the Sahara, torture in Libyan jails and Europe’s indifference to their plight. After winning awards at the V…