LP1076411 Return updated circ object from checkin

Retrieve an updated copy of the circulation object to return to the
caller during checkin.  This ensures the data in the circ object, in
particular date fields, are consistent with the database.

Signed-off-by: Bill Erickson <berick@esilibrary.com>
Signed-off-by: Ben Shum <bshum@biblio.org>