Fix the wrongish way we were doing staff-assisted holds

Fix the wrongish way we were doing staff-assisted holds

Now the patron that a staff user wants to place a hold for is passed
around as a cookie

It's a little unclear when is best from a workflow perspective to kill
said cookie... hrmmm....

Signed-off-by: Lebbeous Fogle-Weekley <lebbeous@esilibrary.com>