Check with CI if video stream is live or not.
IMPORTANT: you must register with ustream and get an api key in order to use this code. Next get an API key and edit the variable called $devkey in [live_model.php] (https://github.com/michaelreynolds/codeigniter-ustream-live-check/blob/master/application/models/live_model.php#L25)