Splitting the magic controller between operations that fetch or alter resources.
Adding a ResourceLinksHydrant.
Now the relationships are hydrated on the resource objects given to the C(R)UD services.
Fixing a small bug in the MagicController.
Merge pull request #20 from GoIntegro/feature/api-51-relate-resources

[API-51] Magically relate resources
Creating and updating now links resources.
Forgot a small detail.
Improving some error messages.
Adding some resiliency to the body parsing procedures.
Forgot that the JSON Schema matcher can only get stdClass objects.
Adding a test for parsing create requests.
Fixing a small bug with the Builder and Mutator services.
Adding some more array normalization.
Adding a small comment.
Merge pull request #21 from GoIntegro/feature/api-51-relate-resources

[API-51] Relate resources when creating or updating them
Refactoring the request body parsers.
Adding some YPath magic.
Partial.
Moved an exception.
Adding some docs.