By ANDREA RODRÍGUEZ, Associated Press HAVANA (AP) — Marylín Álvarez seemed to be just the sort of person that eased American sanctions on Cuba were meant to help. With the aid of money sent by a cousin living in the United States, she began transforming the entrance to her ground-floor apartment into a tiny cafe about four years ago. It was one of myriad small private businesses blossoming on the Communist-led