Always include styles before scripts

This is needed for two reasons:
 1. common.js depends on the CSS being loaded. But $(document).ready does not
    guarantee that all CSS is actually loaded. So all stylesheets needs to be
    included before common.js.
    See http://api.jquery.com/ready/
 2. It is a best practice for speed to put stylesheets before scripts. It isn't
    really relevant nowadays, but in the past, browsers used to wait for scripts
    to execute before stylesheets even started to load.
    http://www.feedthebot.com/pagespeed/style-script-order.html
    (There used to be a PageSpeed Insights rule for this, but it's gone.)