A team of 40 BBC journalists from 12 languages began an 18-day tour of India on a special train on Saturday to cover the ongoing Indian elections. The journalists will visit Ahmedabad, Bombay, Patna, Calcutta, Bhubaneswar, Allahabad and Hyderabad. Here, BBC assignment editor Mark Perrow flags off the journey for the cameras. Photograph: courtesy Rajeev…