Steve Christian, the founder of the Isle of Man's film investment program CinemaNX and former Pinewood Pictures exec, has died at the age of 53. The well-respected industry veteran, who most recently co-produced Fox Searchlight's Untitled A.A. Milne Project with Damian Jones, held a number of government positions on the Isle of Man, a small self-governing tax haven in the Irish Sea between England and Ireland, before turning to the entertainment business. In 2007…