Adding AMD wrapper to lang files

[timrwood]

This addresses #128 and #479.

This changes the way language files are defined. Rather than adding the complex environment forking to each language file, the source files are instead only targeting Node.js.

Then, during the build process, the require('../moment') string is replaced with moment and is wrapped with the AMD/browser code.

// en.js source file
require('../moment').lang('en', {
    // the good stuff
});

// en.min.js file targeted towards browsers and Require.js
(function(){
    function onload (moment) {
        moment.lang('en', {
            // the good stuff
        });
    }
    if (typeof define === "function" && define.amd) {
        define(["moment"], onload);
    }
    if (typeof window !== "undefined" && window.moment) {
        onload(window.moment);
    }
})()

Thoughts @mlegenhausen, @Morriz, and @trondkla?

[timrwood]

Pinging @mlegenhausen, @Morriz, and @trondkla. Any thoughts?

[trondkla]

Looks good!
Will try it out at job when I find the time to upgrade moment.js

[timrwood]

Merging this in, this will go out in the 2.0.0 release