VALLE DE SANTIAGO, Mexico (Reuters) - The rousing trumpet music, the swish of the cape and the shouts of "Ole!" as the bull charges are all familiar to anyone who has seen a bullfight. The unnerving thing in the bullring at this dusty central Mexican town is that bull and bullfighter are standing eye to eye, both about four feet high. The Mexican "dwarf bullfighters" are carrying on a tradition born in Spain along with regular bullfighting, as well as an even longer legacy of "little people" as entertainers. But they say the ring showcases their skill and comic artistry,...