When asking, for a section header, dequeue a CustomHeaderFooterView, and insert a cell into it
func tableView(tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
let view = self.tableView.dequeueReusableHeaderFooterViewWithIdentifier("SECTION_ID") as! CustomHeaderFooterView
if view.cell == nil {
let cell = self.tableView.dequeueReusableCellWithIdentifier("Cell")
view.cell = cell;
}
// Fill the cell with data here
return view;
}