Dean’s Late-Night Battle Cry Likely to Echo From Here On By Mark Z. Barabak and Faye Fiore, Times Staff Writers MANCHESTER, N.H. -- Howard Dean's overheated concession speech in Iowa could prove a damaging turning point in his campaign, intensifying concerns that Vermont's former governor is prone to outbursts and fits of pique that make him unqualified to be president, analysts said Wednesday. The image of Dean repeatedly punching the air in a performance some likened to an emotional meltdown has played endlessly on cable news networks and offered instant fodder for late-night comedy monologues. "He's a very rational, pleasant...