Provide YAML support in config files

[bbossola]

With YAML we will be able to describe entire objects, rather than properties: it fits very well the mechanics for complex configuration.
http://en.wikipedia.org/wiki/YAML
http://yaml.org/

I suggest to use SnakeYAML as java library:
http://code.google.com/p/snakeyaml/

[lviggiano]

related to #14 and #2

[lviggiano]

My initial idea was to implement some mapping between the YAML format and the Properties format as I did with XML (see #5 as implemented in XMLLoader )
The loaders are now pluggable with Loaders.registerLoader(), so I will probably implement just the xml and the properties format, since the parsers for those are already available in JRE, and provide to the user the possibility to register additional loaders to the ConfigFactory.

If I were using YAML I would probably go for SnakeYaml directly which provides a good serialization stack between yaml and java objects. I can't see the advantage to use OWNER in this case.

[lviggiano]

won't fix. at least, not for now.

[randyhbh]

Can we add this support?