Use also folders as keys

[corneyl]

It would be a nice addition if one could also use configuration files nested in folders, which will then be parsed recursively (like is the case with Kohana's CFS), e.g.:

config/
   +-- dev/
      +-- locales/
         +-- en.yml
   +-- locales/
      +-- en.yml
      +-- es.yml

Will result in:

{
   "locales": {
      "en": {
         "foo": "bar"
      },
      "es": {
         "foo": "barra"
      }
   }
}

[pilwon]

@corneyl This would be a great addition. Looking for contributor-