By SARAH FITZMAURICENever too old: Justin, 17, seemed keen to visit Hamley's toy shop with Willow and Jaden Smith and couldn't wait to try out the goods on offerJustin Bieber may have recently turned 17 years-old and is on the brink of becoming a man but last night he proved he is just on big kid at heart. The singing sensation has taken his tour to London and while the capital has plenty to keep