Fix for IE 11

The current ```userAgent``` from **IE 11** is ```"mozilla/5.0 (windows nt 6.3; trident/7.0; .net4.0e; .net4.0c; rv:11.0) like gecko"```.

[Here](http://msdn.microsoft.com/en-us/library/ms537503(v=vs.85).aspx#UnderstandUA) a little bit more of background on  this userAgent declaration.

My current solution is rather inefficient, but I have to admit I'm not good with javascript regex. Do you have any idea on how we may improve the regex and being backwards compatible at the same time?