A STIFF wind was blowing through Chelsea, driving the cold rain sideways. It was last Thursday, early evening, just after quitting time. Seven in the evening is hardly a decent hour for a must-attend party, let alone one held outdoors in a space sheltered, though barely, by the elevated train tracks of the High Line. Still, New York being New York, there were already people lining up by a half-shuttered riot gate, umbrellas blown inside-out, waiting to get in.