For virtually all of his career, legendary oil trader Andy Hall was a permabull when it comes to the price of oil. While that served him well for much of the past three decades as oil prices rose alongside China's ascent and relentless demand for crude, resulting in a personal fortune and making Hall one of the richest and most successful commodity traders in the world, it also was the reason for his demise, when after several years of declining oil prices following the OPEC near collapse on Thanksgiving Day 2014, Hall - who was unwilling to change…