[devtools] make a copy of the xvfb-run script so we can kill it properly Since changeset a3d3bdd46463 we don't run firefox directly but through a wrapper script. This meant that on stopping the test, we would kill that wrapper script but leave the Xvfb server and firefox processes running. So make a local copy of xvfb-run, and make it kill Xvfb when it goes down, not just when its client exits.

$(document).ready(function() {
    $('a.rhythm').click(function (event){
        $('div#pageContent').toggleClass('rhythm_bg');
        $('div#page').toggleClass('rhythm_bg');
        event.preventDefault();
    });
});