Docs performance: CSS/JS concatenation & minification

Rebuilt the docs for compiling a concatenated & minified css file from all the less files. Same with js, where all js files get concatenated by prepending to the site's js file. More details in the commit messages.

This reduces css/js request from more than 20(!) to a total of 2 and 3 for IE7 users (excluding jQuery, html5shiv). This all enhances initial rendering performance of the docs site and reduces bandwidth usage, so it's an attempt to solve #67 too.

All done with [CodeKit.app](http://incident57.com/codekit/). But for the less compilation, `lessc`'ing the docs.less file to css/docs.min.css would work too (yay less imports). As for js, a build script would have to be used when not using an app like CodeKit.