Styles & scripts optimization in the document head

CSS must always be included before JS in the document head to allow the CSS files to be downloaded in parallel.

I just moved all the script tags in:

octopress/.themes/classic/source/_includes/head.html

to go after:

{% include custom/head.html %}

so that if custom css and scripts are added in the right order, the overall order will still be CSS before JS.

Hope that all made sense.

-Esteban