Refactor for Berkshelf

Lots happening here:

* The cookbook now can be used w/ Berkshelf
* Structure follows current, accepted convention for a cookbook
* README cleaned up:
    * Includes all attributes
    * Follows pattern set down by Berkshelf
    * More explicit
    * Example data bags are inline, instead of separate files
* Version number reflects current version of twilson63/s3fs-recipe

This cookbook converges using Vagrant, though there are some caveats:

* Must specify the path to your data bags in the Vagrantfile
* A data bag following the example in the README must exist