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 
But ExclusionStrategy interfaces is ours, isn't it?

On Wed, Oct 29, 2014 at 6:52 PM, Otávio Garcia <notifications@github.com>
wrote:

> In
> vraptor-core/src/main/java/br/com/caelum/vraptor/serialization/JSONSerialization.java:
>
> > @@ -15,6 +15,8 @@
> >   */
> >  package br.com.caelum.vraptor.serialization;
> >
> > +import com.google.gson.ExclusionStrategy;
>
> This class is a part of our public API, and we can't add vendor lock-in
> artifacts here. All public API can't knows about any implementation.
>
> —
> Reply to this email directly or view it on GitHub
> <https://github.com/caelum/vraptor4/pull/859/files#r19575044>.
>



-- 
Rafael Ponte
TriadWorks | Formação Java
http://cursos.triadworks.com.br