[WIP] V2

Hey,

I started working on the "v2", kind of a rewrite of the FSCHateoasBundle, but as a library, and with new things.

This is indeed a WIP, however in the current state, it can serialize links in xml from simple yaml/annotations configuration. You should be able to see the big picture of how I want to do it.
https://github.com/adrienbrault/Hateoas/blob/8217206bddab7e91ee42d8a00ef480336adce3aa/tests/Hateoas/HateoasBuilder.php#L22-L38

I'm creating a pull request now to get your feedback.