Natasa Vojnovic in todays New York Times:Photo Michael Falco for The New York TimesNO FRILLS The designer Alexander Wang with the models Missy Rayder, center, and Natasa Vojnovic in his New York studio. In five years Mr. Wang, 25, has built a $25 million companyby Ruth La FerlaDON’T tell Alexander Wang that blue is the new black or that wedge-heel boots are the season’s must-have. Such airy