Use page URL to construct meaningful image name.

def namer(cls, imageUrl, pageUrl):
        """Use page URL to construct meaningful image name."""
        parts, year, month, stripname = pageUrl.rsplit('/', 3)
        stripname = stripname.rsplit('.', 1)[0]
        parts, imagename = imageUrl.rsplit('/', 1)
        return '%s-%s-%s-%s' % (year, month, stripname, imagename)