By JODY THOMPSON Dedication: 50 Cent lost more than four stone in just two months for his role in Things Fall Apart He famously launched onto the music scene with his 2003 multi-million-selling album Get Rich Or Die Tryin' - and 50 Cent has shown his dogged commitment to success in his latest film role.The 35-year-old rapstar - real name Curtis Jackson - underwent drastic weightloss to play an