IE detection code was refactored

http://tanalin.com/en/articles/ie-version-js/

Internet Explorer browser of versions 10 and older can be detected in JavaScript by checking existence of the nonstandard document.all object available only in IE10 and older. 

Such objects for versions of IE up to 10 inclusive are listed in the following table. 
IE ver	Supported standard object
 10+	window.atob
 9+	document.addEventListener
 8+	document.querySelector
 7+	window.XMLHttpRequest
 6+	document.compatMode