A MILE NORTH OF the chaotic heart of downtown Rangoon, where electrical wires dangle haphazardly overhead and street vendors hawk roasted pig intestines, sits an upscale complex of 240 luxury residences overlooking the iconic Shwedagon Pagoda and a serene man-made lake. Marketed to wealthy expatriates and foreign businesspeople on extended stays in Burma’s bustling commercial capital, the newly built Shangri-La Serviced Apartments advertise …