THE POST-MODERNIST FOOLS AMONG US -- Falstaffs At The Gates... A grand new production of Henry IV parts 1 and 2 has come to New York. Condensed into one four-hour performance, it has been received with favorable reviews, and Kevin Kline's performance as Sir John Falstaff is itself worth the price of admission: (On the battlefield of Shrewsbury) PRINCE HAL: Why, thou owest God a death. (exits) FALSTAFF: 'Tis not due yet, I would be loath to pay him before his day -what need I be so forward with him that calls not on me? Well, 'tis no matter, honour...