HOUSTON/NEW YORK (Reuters) - The global oil refining industry is facing a reckoning from falling fuel demand that is the deepest and fastest ever.Within weeks, the industry will need to cut output by 30% or more as the coronavirus pandemic keeps much of the world at home with little need to drive or fly. Smaller and financially weak oil refiners may not emerge from the crisis, say refining consultants and traders. "This Covid isn't going to kill the refining industry, but it might kill those..