Stop the interface

        :rtype: None

def stop(self):
        """
        Stop the interface

        :rtype: None
        """
        self.debug("()")
        # Stop the plugins
        for plugin in self.plugins:
            try:
                plugin.stop()
            except:
                self.exception(u"Failed to stop plugin {}".format(plugin.name))
        super(CrowdController, self).stop()