add sru support

[Aaron Swartz]

Karen points out it'd be nice for libraries if we had an SRU interface that returned MARC records so that they didn't have to buy records. This is probably a low priority since we're focused on API and web users at the moment, but it'd be a nice service.

http://www.loc.gov/standards/sru/specs/search-retrieve.html#records

[Edward Betts (edwardbetts)]

We're not going to generate MARC records, do we still want to provide SRU, or can I close this bug?

[George (george-archive)]

Funny thing is, when I mentioned this to Brewster yesterday, just to confirm his opinion, he said "MARC export would be a nice feature".

So, that means we should keep this around, but there's no way we can work on it until Upstream is out the door.

[Edward Betts (edwardbetts)]

We can provide SRU for books with a MARC record. If a book doesn't have a MARC record it won't be available via SRU.