Adding PHP, YAML, ... adapters?

[dereuromark]

Do people currently prefer the INI files and adapter?
Or shall we also add others? What are your preferred config files?
Feel free to comment and let us know what is missing terms of config file support.

[LubosRemplik]

Personally I prefer Yaml config files, using this https://github.com/guemidiborhane/yaml-config

[dereuromark]

@LubosRemplik Do you or anyone else wants to try a yaml adapter here?