Fifty years ago, in a fit of pique, Ferruccio Lamborghini—a maker of tractors and other industrial equipment—started his own sports-car company after a run-in with Enzo Ferrari over a car that Lamborghini had ordered. To mark the 50th anniversary of that occasion, Lamborghini has unveiled the Veneno supercar, a 750 hp V-12 two-seater loosely based on the Aventador. (The company has kept to its convention of using the names of fighting bulls: Veneno—Spanish for “venom”—is infamous for killing the matador José S…