Render markdown with metalsmith

[JuanCaicedo]

Based of the discussion in #20, here's the version I have working http://www.juancaicedo.com/oboe.js-website/! I left all the original code untouched and brought over as much functionality as possible. Here's a main outline of the additions:

• deploy.sh deploys the gh-pages directory to GitHub pages
• build-static.js builds the static pages using Metalsmith
• src/ is a copy of all the markdown files used for building pages, as well as all the static assets
• helpers/ is for any handlebars helpers that are used within the markdown files. These are rendered in place before the markdown is rendered, and before the full page is assembled.
• layouts/ is for handlebars layouts for the whole page
• metalsmith-plugins/ is for additional metalsmith plugins. The only metalsmith plugin for markdown uses marked and we needed supermarked. I didn't want to deal with publishing and maintaining a new plugin, so I just included it in the repo.
• partials/ for handlebars partials which are rendered at the time the layout is assembled.
• tests/ for tests

There are a few regressions, namely:

• No PDFs
• Improve this page doesn't show up in the side navigation bar

Please take a look and see if there's anything else that seems off from the site. Using this would help us stop the nodejitsu troubles!

[JuanCaicedo]

Given that the normal site has been up and running smoothly for the last few months, I'm going to close this PR