Used to load files synchronously. (useful to show progress of loading files)

load-files.js

function loadFiles(files, fn) {
    var head = document.head || document.getElementsByTagName('head')[0];
    var counter = files.length;
    callback(); // To cover case when there are no files available
    files.forEach(loadFile);
    function loadFile(file) {
        var fileref = document.createElement('script');
        fileref.setAttribute('type', 'text/javascript');
        fileref.setAttribute('src', file);
        head.appendChild(fileref);
        // Used to call a callback function
        fileref.onload = function () {
            counter--;
            callback();
        };
    }
    function callback(){
        if(counter <= 0){
            if(fn){
                fn();
            }
        }
    }
}