Fannie Mae continued the process of making itself over this week as the government-sponsored enterprise announced another round of personnel shakeups and revealed that it would not dole out bonuses for its top executives for 2004. In papers filed with the Securities and Exchange Commission this week, Fannie officials said three senior vice presidents whose duties covered the GSE’s accounting were stepping down. Janet Pennewell, who oversaw the company’s financial reporting, Jonathan Boyles, who supervised…