“Change is neither good nor dangerous. It merely is,” declares Donald Draper, the unflappable star of “Mad Males”, a tv drama set in Nineteen Sixties adland. Not all promoting executives share his sangfroid. In the present day, expertise is altering the business sooner than at any time since Mr Draper’s period. The result’s a reshaping of Madison Avenue that’s leaving some admen choking on their Previous Fashioneds.