Return html saying whether this Action is reverted by another
        one or reverts another one.

def _status(self):
        """Return html saying whether this Action is reverted by another
        one or reverts another one."""
        text = ""
        # Turns out that is related field in null, Django
        # doesn't even make it a property of the object
        # http://code.djangoproject.com/ticket/11920
        if hasattr(self, "reverts"):
            text += '(reverts <a href="%s">%s</a>)<br/>' % (
                self.reverts.get_absolute_url(),
                self.reverts.id
            )
        if self.reverted:
            text += '(reverted in <a href="%s">%s</a>)<br/>' % (
                self.reverted.get_absolute_url(),
                self.reverted.id
            )
        return text