Merge all javascript files to one file

grunt-usemin (- https://github.com/yeoman/grunt-usemin) could help.

This one works on me

mainhub.js

function callAll(jsfiles) {
    var src = document.createElement("script");
    src.setAttribute("type", "text/javascript");
    src.setAttribute("src", jsfiles);
    document.getElementsByTagName("head")[0].appendChild(src);
}
callAll("your/path/to/a/jsfile1.js");
callAll("your/path/to/a/jsfile2.js");
callAll("your/path/to/a/jsfile3.js");

then all you have to call is the mainhub.js on your header

<script type="text/javascript" src="your/path/mainhub.js" ></script>