Teach OpenLibrary.pm how to extract ebook links from OpenLibrary results

Teach OpenLibrary.pm how to extract ebook links from OpenLibrary results

If the Internet Archive has an available ebook, then OpenLibrary will
provide links to it in various formats. For now, we return the results
as a plain set of <div> elements with class attributes denoting what
kind of ebook was returned; i18n will have to take care of providing
an actual label. Oh, and I guess we want to turn these into actual
<a> links...

Signed-off-by: Dan Scott <dscott@laurentian.ca>
Signed-off-by: Lebbeous Fogle-Weekley <lebbeous@esilibrary.com>