LONDON (Reuters) - Britain's biggest theme park has called off the country's first "National Muslim Fun Day" because of lack of interest, the park said Wednesday. Alton Towers in central England was to open on September 17 for Muslims -- with halal food, a strict dress code and prayer areas. Music, gambling and alcohol were to be banned for the day and theme park rides such as "Ripsaw," "Corkscrew" and "Charlie and the Chocolate Factory" all segregated by sex. But the park said the event's organizers, Islamic Leisure, who rented the park for the day and were marketing the event,...