Off to Shanghai.   By the standards of Hong Kong, a huge, messy, amorphous megalopolis, with a population of 25 million spread across the delta of the River Yangtse and a long drive in from the airport.   It’s hard to believe the ups and downs of its history:  settled by  the British after the Treaty of Nanking in 1842, foreign men, according to the guidebook, ‘found sexual solace in service professionals’;  they were joined by the French and Americans and the Sassoons and Kedouries from Baghdad;  then the Japanese came after the Sino-Japanese war of 1895 and the White Russians after 1917.   The Japanese took over in 1937, the Americans on 15 August 1945, and the Communists on 25 May 1949.   Now, under the Communists, it is once again the ultimate capitalist city.