fix #31, javascript-less subject list on home page

The changes for #35 enable setting css rules based on the presence of javascript, so I used that to disable hiding courses from the list on the main page when javascript is disabled.

I can verify that it doesn't break functionality when javascript is _enabled_, but shutting off javascript on my local machine breaks `less.js`. I couldn't get my setup to work with DEBUG turned off at all. But at least it doesn't break things for people for whom it wasn't broken before.