Fixed title/author display at checkout for non-pre-cat items.

Fixed a display problem on checkout where items that were formely pre-cats
were still displaying the pre-cat data. Now it will make sure the item is
still a pre-cat before using the dummy data.

Signed-off-by: Steven Callender <stevecallender@esilibrary.com>
Signed-off-by: Ben Shum <bshum@biblio.org>