Judgment on DeltchevBy: Eric Ambler Fosters dramatic skill is well known in Londons West End theaters. So perhaps it wasnt so surprising when he was hired by an American newspaper publisher to cover the trial of Yordan Delchev for treason. Accused of membership in the sinister Officer Corps Brotherhood and of masterminding a plot to assassinate his countrys leader, Delchev may in fact be a pawn and his trial all show. But when Foster meets Madame Delchev, the accuseds