Use jekyll as a template engine

Added Jekyll static page generation syntax.

This allows for better encapsulation of templates and stuff (and is a lot more DRY then repeating the same html in all files). Jekyll supports lots of nice things like partial templates and aggregates (e.g. a blog template with posts in different files and a `{% for posts in site.posts %} {{ post.title }} {% endfor %}` to iterate through them).

The downside is of course that it's a preprocessor to the actual site, but since one can always run the `jekyll` command locally to generate a static fileset to host anywhere (e.g. s3) that shouldn't be a problem. It's also fairly easy to dump it all on heroku using the quite nice multithreaded unicorn webserver.