Intl global in ECMAScript Internationalization API 1.0 (ECMA-402)

Intl is now a standard global for browsers, defined in:
http://www.ecma-international.org/ecma-402/1.0/#sec-8

It's supported by all major browsers except Safari:
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl

…and Safari plans to add it:
https://bugs.webkit.org/show_bug.cgi?id=90906