mod_pep_atom_categories: Add a module to index categories in Atom entries
A new node is created for each category, named category-<the category>, which
contains a list of all node/item tuples having said category as a tag.
2c07bcf56a36d6e74dc0f5422e89bd61f4d31239 0.8-diverge
1656d4fd71d07aa3a52da89d4daf7723a555e7dd last-google-code-commit