'Parse out the lxml root in each category'

def parse_categories(self):

    log.debug(('We    are    extracting    from    %d    categories' % len(self.categories)))
    for category in self.categories:
        doc = self.config.get_parser().fromstring(category.html)
        category.doc = doc
    self.categories = [c for c in self.categories if (c.doc is not None)]
