FOR a period of 200 years, starting in the first quarter of the 18th century, Java was the key island of the Netherlands East Indies empire. Under Dutch rule Java became known as the garden of the tropics, one of the best-governed tropical islands in the world. It was a wonder of colonial management, a land of punctual railroads, well-run schools, vast agricultural estates, swank mountain resorts. You could telephone any point on the island from