IE11 support added

IE11 support added based on two different useragent possibilities:
* Mozilla/5.0 (Windows NT 6.3; Trident/7.0; rv 11.0) like Gecko
(http://stackoverflow.com/a/17447718)
* Mozilla/5.0 (IE 11.0; Windows NT 6.3; Trident/7.0; .NET4.0E; .NET4.0C; rv:11.0) like Gecko
(http://www.engadget.com/2013/03/25/ie-11-says-it-is-like-firefox/)