Container

This PR contains the project and software definitions for chef-container - a project that will build a customized package for Docker (and maybe other) containers. 
you'll also want to construct your env hash like this now:

https://github.com/opscode/omnibus-chef/blob/master/config/software/chef.rb#L31-L32

the with_embedded_path() helper hides all this silly path_key stuff now.