Refactor into executable

Attempting to clean this up with the following goals:
* marina runs as an executable in a folder with a jekyll site template
* config is pulled from a `.marina.json` (configurable from command line)
* Front matter is set on the various pages before rendering so it can be used in liquid templates

Current major issues:
* Hacked in a `send` to set the front matter data on a Jekyll page
* Lots of conflating of a projects `name` with its folder name (currently they must match...)
* Copying of defined index file is hacky
* Lots of things should be configurable that are just hard coded right now.
* No tests...  

All in all, this did not turn out as cleanly as I'd hoped.  I don't know the Jekyll code base well enough to tie cleanly into it, but maybe we can get there.

@tfausak @camdez  thoughts?  I think this should be a decent starting point for now