[uf-new] hProduct: more around product category

[Myers, Jay]

I've added a straight "category" to the schema, in addition to rel-tag,
to cover those instances where using rel-tag isn't possible. An example
would be when a publisher adds a category but cannot make it a clickable
link (thank you for the tip on this, Andy Mabbett).

I would think there could be multiple category nodes in the markup to
represent and replicate the hierarchical labels that most publishers
employ to categorize their products, similar to unordered/ ordered HTML
"breadcrumb" markup used on many sites.

Any comments or suggestions would be appreciated!

J

Jay Myers
Lead Web Development Engineer
Online Solutions, BestBuy.com
@jaymyers