Bug 19457: Handle 'PREVISSUE' return by CanBookBeIssued from SIP (CheckPrevCheckout)

Bug 19457: Handle 'PREVISSUE' return by CanBookBeIssued from SIP (CheckPrevCheckout)

If CheckPrevCheckout is set to Do, then checkouts are blocked at the SIPServer

To test:
- Do not apply this patch
- Set CheckPrevCheckout to "Do", or "Unless overridden, do"
Verify the SIP server is blocking checkouts with this setting set
- Apply this patch
- Note that the checkout is now allowed, with a screen message telling
the borrower they've issued the item before.

Signed-off-by: Liz Rea <wizzyrea@gmail.com>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>