Though Georgetown Cupcake was holding off opening until Valentine's Day, their debut yesterday seemed to be missing something — cupcakes. Last night, potential customers were turned away by an apologetic sign, "We are so sorry! We have completely run out again." This was one of many times the tiny boutique bakery off M Street (right across from Quick Pita, a Hoya mainstay) had to temporarily shut down to keep up with orders. It was two......