TUNIS – Tunisia’s interim leadership promised a “complete break with the past” and freed political prisoners yesterday in efforts to appease street protesters who want a total purge of the old guard. Five days after veteran strongman Zine al-Abidine Ben Ali fled to Saudi Arabia with some of his wealthy entourage, former political allies, including the prime minister, were still trying to coax opposition figures into a national unity government that can restore order and oversee promised free elections.