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.
//Popups

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

// End of popups

// Unwatch

importScript('http://en.wikipedia.org/w/index.php?title=User:Alex Smotrov/wlunwatch.js');

// End of unwatch

// install [[User:Cacycle/wikEd]] in-browser text editor
mw.loader.load('https://en.wikipedia.org/w/index.php?title=User:Cacycle/wikEd.js'
+ '&action=raw&ctype=text/javascript');


// Begin "edit section 0" function


$(function () {
    var x;
    if (!(x = document.getElementById('ca-edit') )) return;
    var url;
    if (!(url = x.getElementsByTagName('a')[0] )) return;
    if (!(url = url.href )) return;
    var y = mw.util.addPortletLink('p-cactions', url+"&section=0", '0', 'ca-edit-0',
                           'Edit the lead section of this page', '0', x.nextSibling);

    y.className = x.className;  // steal classes from the the edit tab...
    x.className = 'istalk';     // ...and make the edit tab have no right margin

    // exception: don't steal the "selected" class unless actually editing section 0:
    if (/(^| )selected( |$)/.test(y.className)) {
        if (!document.editform || !document.editform.wpSection
            || document.editform.wpSection.value != "0") {
            y.className = y.className.replace(/(^| )selected( |$)/g, "$1");
            x.className += ' selected';
        }
    }
});

//
// End "edit section 0" function