NEW YORK — Dozens of mournful fans of Flaco the Eurasian eagle-owl gathered in New York City on Sunday to say goodbye to the beloved celebrity creature who became an inspiration and joy to many as he flew around Manhattan after someone let him out of his zoo enclosure.A memorial featuring speeches and songs was held in the late afternoon in Central Park at what organizers call Flaco’s favorite oak tree.Flaco was found dead on the Upper West Side on Feb. 23 after apparently hitting a…