CEMENT SHOES.COM Eager investors are buying up shares of an intrepid new company, which is cornering the market in international trade, financing and entertainment. Or to be specific: drugs, loan sharking and prostitution. The reinvented Mafia has incorporated, offering stock options, a Web Site and online trading. The future is here, and Remo hates it.  Mafia scum have burned down his house, Chiun isn't speaking to him and nobody is answering his ad for an assassin's apprentice.  As an ambitious Don keeps one eye on the Dow, the suffering Dr. Harold Smith lovingly fingers his cyanide pill while the retiring U.S. President, in a departing "salute," puts CURE in the hangman's noose