The shakeup continued at Fannie Mae this month with the announcement of more new executives and the departure of the GSE’s portfolio manager and top attorney. Ann Kappler, an executive VP and general counsel at Fannie, will be stepping down from her post at the end of the year to join lobbying firm Collier Shannon Scott. Kappler was in charge of Fannie’s stable of more than 120 attorneys and provided legal advice to Fannie’s top…