Note: After saving, you have to bypass your browser's cache to see the changes. Internet Explorer: press Ctrl-F5, Mozilla: hold down Shift while clicking Reload (or press Ctrl-Shift-R), Opera/Konqueror: press F5, Safari: hold down Shift + Alt while clicking Reload, Chrome: hold down Shift while clicking Reload.
importScript("MediaWiki:UserMessages.js");

// From [[en:User:Lupin/autoedit.js]]
function getParamValue(paramName) {
        var cmdRe=RegExp('[&?]'+paramName+'=([^&]*)');
        var h=document.location;
        var m=cmdRe.exec(h);
        if (m) {
        try {
                return decodeURIComponent(m[1]);
        } catch (someError) {}
        }
        return null;
}

document.write('<script type="text/javascript" src="' 
            + 'http://commons.wikimedia.org/w/index.php?title=MediaWiki:DeleteKeep.js' 
            + '&action=raw&ctype=text/javascript&dontcountme=s"><\/script>');
//[[MediaWiki:DeleteKeep.js]]

  document.write('<script type="text/javascript" src="'
             + 'http://commons.wikimedia.org/w/index.php?title=User:Polarlys/quickbar.js'
             + '&action=raw&ctype=text/javascript&dontcountme=s"><\/script>');
 //[[User:Polarlys/quickbar.js]]

// [[:en:User:Lupin/popups.js]]

mw.loader.load(
             'https://en.wikipedia.org/w/index.php?title=User:Lupin/popups.js'
             + '&action=raw&ctype=text/javascript&dontcountme=s');