added fullscreen detection

If we want to detect the browser I think we better use the property approach which is more accurate. Also the MSIE regex will not detect IE11 since IE11's user agent is: " Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.3; Trident/7.0; .NET4.0E; .NET4.0C)"
If we want to detect the browse's rendering engine (webkit, firefox, trident ...) we should change the property name to maאch and fix the regex