The call came a year after photos of Jewish children dressed in blackface during Purim drew widespread condemnation. (JTA) — A year after photos of Jewish children dressed in blackface during Purim drew widespread condemnation, several leading Jewish groups in the New York area have issued stern guidance in advance of next week’s holiday.The Anti-Defamation League sends a similar letter out annually before Halloween, according to Alexander Rosemberg, the group’s deputy director for New York and New Jersey, but this is the first time that it has produced one for Purim, a festive holiday traditionally celebrated with costume parties.The Lakewood...