JavaScript Improvements

This pull request includes some basic improvements to marginalia's javascript. I updated jQuery from 1.4.4 to 1.7.1 and made some minor improvements to app.js to make the floating TOC precise. The positions were previously being calculated before the syntax highlighter kicked in, so clicking marginalia.parser link at the top of the page would scroll down but have marginalia.html as the floating TOC value. That should all be fixed now. It should also be slightly more performant as I commented out console.log statements which tend to generate errors in older browsers. 

Please let me know if you envision any other HTML/CSS/JS improvements in the future (I'm fairly new to clojure - but I'm making my way through your book)

Regards,
Ivan.