Numerous minor tornadoes whirl across the steppe in director Sergei Dvortsevoy's Kahzak-language film “Tulpan,” but no one seems to care. The wind, the tornadoes and the general squalor of life for a rural nomadic sheepherder in Kazakhstan is completely taken for granted, buried in the daily routine of eking out a living.    The average viewer, on the other hand, is more likely to be taken aback, but Mr. Dvortsevoy's film casually refuses to accept or even acknowledge its foreignness, which gives “Tulpan” a warm, natural feel that colors the mundane, sometimes disturbing reality on the steppe. It's unlikely that many viewers would enter into “Tulpan” with a rosy-hued vision of Kazakhstan, but the film gives us all of the unpleasant realities of nomadic life — constant blowing sand, filthy clothes, rotted teeth and cantankerous animals — while also giving us rare glimpses of the triumphs too, like the dramatic on-screen birth of a lamb that represents the film's highest dramatic peak.