ON THE heels of President George Bush's call to shift away from United States reliance on Middle East oil, a contingent of Texas oilmen and bureaucrats from Havana gathered in Mexico to discuss a nervy alternative: Cuba. Despite Washington's 45-year trade embargo against Fidel Castro's Government, Cuban officials are courting US energy companies to produce oil in its territorial waters. Late on Friday, an agency of the US Treasury Department, the Office of Foreign Assets Control, asked Starwood Hotels, the company that owns the Sheraton Hotel in Mexico City where the three-day meeting was being held, to require the...