split front matter from markdown (compatiblity with jekyll)

[jmlich]

Jekyll flawored Markdown documents could contain front matter which is YAML configuration prefixed into document. It allows customization of the web page. For example:

---
layout: post
title: Blogging Like a Hacker
---
# Blogging Like a Hacker
content

This could be used to define "Data" variables like title, etc.