#304: Fixed device detection code: Windows Phone 8.1 was detected as And...

Windows Phone 8.1 [fakes user agent string to be detected as Android or iPhone](http://www.neowin.net/news/ie11-fakes-user-agent-to-fool-gmail-in-windows-phone-81-gdr1-update). This fixes some problems with mobiles sites, but introduce some other problems. Currently `fastclick` incorrectly detects Windows Phone 8.1 device and breaks user interaction with site. This pull request should fix the problem and `fastclick` should work on Windows Phone 8.1 just as good as on Windows Phone 8.0.