'Forget SeenEntry with :title:. Return True if forgotten.'

def forget(self, task, title):

    se = task.session.query(SeenEntry).filter((SeenEntry.title == title)).first()
    if se:
        log.debug((u"Forgotten    '%s'    (%s    fields)" % (title, len(se.fields))))
        task.session.delete(se)
        return True
