OpenLibrary links display in Firefox and Internet Explorer less than ideal & need proxying for borrowed content

In master, the OpenLibrary links display properly in Chrome but the event model seems to be different for Firefox and Internet Explorer, where the entire list of ISBNs gets run through the fetchOpenLibraryLinks() method for each record when it is displayed (rather than just once for the entire page). This results in duplicate OL links being appended for each record, rather than just one.

Setting a global var fetchedOpenLibraryLinks prevents successive iterations from fetching and displaying the content - it doesn't feel like the proper way to resolve the problem, but it does resolve it, and that's better than the current situation.

Also - "Borrow online" links need to be proxied to support remote access, so offer var localProxyPrefix for that purpose.