Fixed IE detection

navigator.appName is still "Microsoft Internet Explorer" for IE6-10, and "Netscape" for IE11 (so I'm told [1]), neither of which contains "trident".

Instead, combine the older "microsoft" match (which still works for IE<11) with a test for "trident" on the user agent string.

[1] http://stackoverflow.com/a/17907562
Merge pull request #1018 from jefferyto/patch-1

Fixed IE detection