def real_ids(type)

      Dir[File.join(dir_for(type), '**', '*.json')].inject([]) { |a, p|
        doc = do_get(p)
        a << doc['_id'] if doc
        a
      }.sort
    end
def real_ids(type)

      Dir[File.join(dir_for(type), '**', '*.json')].inject([]) { |a, p|
        doc = do_get(p)
        a << doc['_id'] if doc
        a
      }.sort
    end
Returns a sorted list of all the ids for a given type of documents.

 Actually reads each file and returns the real _id list