[schema, old instance] restore some pre 3.5.10 bw compat as some old instances may still have this, and add migration so we can remove it at some point
$(document).ready(function() {
$('a.rhythm').click(function (event){
$('div#pageContent').toggleClass('rhythm_bg');
$('div#page').toggleClass('rhythm_bg');
event.preventDefault();
});
});