>> Open City, the coffeehouse, diner and bar in Woodley Park, is celebrating its 2nd birthday tonight by offering diners their choice of a free cup of Tryst blend coffee, a glass of champagne, or a piece of chocolate birthday cake. >> Homegrown online fashion purveyors Unsung Designers are heading to New York, but tonight they’ll be hosting a final D.C. trunk sale from 6 to 9 p.m. at 2412 18th Street NW in…