schema.org - remove AggregateOffer, itemOffered; add price=0.00

[Dan Scott]

As our record details page lists each copy as a separate Offer (well, in many cases anyway, unless paging gets invoked), the AggregateOffer entity is not really necessary--and using it on the same page as separate Offer entities is not recommended by at least one search engine (per Google https://support.google.com/webmasters/answer/146750?hl=en says a given page should include "_one_ of the following: Offer or Offer-aggregate", and indeed the Google Structured Data testing tool gets confused when both are included).

We use the "offers" property to link the Product to the Offer, so there is no reason to use a reciprocal "itemOffered" property to link back to the Product from the Offer. The circular reference confuses some tools (http://rdfa.info/play) and may complicate general processing, so let's simply remove it.

[Dan Scott (denials)]

See the top two commits at http://git.evergreen-ils.org/?p=working/Evergreen.git;a=shortlog;h=refs/heads/user/dbs/deaggregate_offers

[Ben Shum (bshum)]

Works for me. Thanks Dan, pushed to master for 2.7!