Adds metadata to the products and breadcrumbs to improve indexing on search engines.
You can test the data that are read by the search engines using this tool:
http://www.google.com/webmasters/tools/richsnippets
The "brand" meta is passed only if the product's attribute set using the product attribute "manufacturer" and the attribute "manufacturer" is set for that product.
The "category" meta is passed only if the current category has been set the attribute "Rich Snippets Category".
The items listed in this attribute are the categories used by Google.
