Add JSON versioning capability

This PR add JSON versioning capability to VRaptor4.
One of the most strategies used for API versioning is through URI. 
With this PR, one can do API versioning allowing the controller to build a result based on URI parameter. 

A sample example of usage follows:
```java
@Get("/example/{version}")
public void example(String version) {
	Object response = new Object();
	result.use(Results.json()).version(version).from(response).serialize();
}
```

@adolfoweloy @andrelrs 
Sorry, but I disagree to expose vendor lock-in interfaces to your public API.

Exposing a `since` method that receives a `double` allow us to implements the same behaviour using any another Json API. There are no vendor lock-in in our public API, only a single `double`.

Exposing vendor lock-in APIs like `ExclusionStrategy` to our public API its to dangerous because forbids if someone wants to add another implementation to JSON serialization like Jettison or native Json Java EE API. Public API can't knows about implementations.

Some days ago we accepted a pull request that exposes `builder`, so you can override `GsonBuilderWrapper` to add your customizations.