Tested on iOS, Android 2.x, Chrome for Android, Safari on MacBook Pro Retina, Firefox mobile (beta) for Android, Opera Mobile (Android).
Detect retina support for a huge amount of devices by Thomas Fuchs
Please move this into Browser.js to be more in ine with other Leaflet code
Move `isRetina` method from Util to Browser
Merge pull request #854 from sxua/master
Detect retina support snippet by Thomas Fuchs