[test_citematic.pl] Narrowed an ambiguous test.
[Get.pm] Be more careful with $1 and $2.
[Get.pm] Fixed a cookie-handling bug.

If the scan picked up the wrong cookie, it would continue to do so even after a new cookie was obtained if the new cookie didn't actually replace the old one.
[Get.pm] Produce hyphenated ISBN-13s.
Support whole books.