Six Billion and Counting. Three days before the world's population officially reaches six billion, correspondents around the globe report on the problems linked to such a statistic. Edward Stourton discovers family-planning policies are failing in India while, in northern Italy, Beppe Severgnini finds career-orientated women blamed for a baby drought. Plus reports from Gaza and Georgia, USA. Producer Lucy Hetherington ; Editor Fiona Murch (S)