New content model

*Not ready yet, WIP*

* [ ] Copy content from pages & posts over to destination directory intact
* [ ] Process markdown content matching glob to HTML
* [ ] Remove processed markdown content
* [ ] Attempt to allow for backward compatibility
* [ ] Refactor, this will be a mess
For reference, 

``` Coffeescript
if @config.paths.markdown? #backwards compatibility for lineman blog
  grunt.file.expand(@config.paths.markdown)
```