[toward-py3k] remove import with_statement (part of #2711624)
They are unneeded since we dropped python 2.5 compatibility. This will help
Python 3.3 experimentation.
$(document).ready(function() {
$('a.rhythm').click(function (event){
$('div#pageContent').toggleClass('rhythm_bg');
$('div#page').toggleClass('rhythm_bg');
event.preventDefault();
});
});