JUDGING from the number of cranes that dot the city’s skyline, Singapore is booming. In the last few years, casinos and hotels have sprung up; museums and galleries in former colonial landmarks have flung open their doors; and international designers have staked out prime real estate alongside up-and-comers just starting to make their fashion mark. Throughout the city, street vendors and sleek restaurants — new and well-established — serve up the city’s renowned mix of Malay, Chinese and Indian ethnic cuisines. And, best of all, sexy lounges and rooftop bars are helping the city-state shake off its formerly staid image.