ACQ invoice search persistence repaired

Use XUL cookieService / cookieManager for managing cookies in embedded
web pages, since dojo.cookie cannot manage cookies within xulrunner.

Persist cookies for 30 days.

Signed-off-by: Bill Erickson <berick@esilibrary.com>
Signed-off-by: Kathy Lussier <klussier@masslnc.org>