ff4j-aop is only able to proxy the first class (ordered by qualified name) matching an interface with a @Flip method.

Hi Cédrick,

Thanks for FF4J, I am playing with it and it looks great !

It takes me some time to understand why this example was not working :
```java
public interface GreetingService {
   @Flip(name="language-english", alterBean="greeting.english")
   String sayHello(String name);
}

@Component("greeting.english")
public class GreetingServiceEnglishImpl implements GreetingService {
    public String sayHello(String name) {
      return "Hello " + name;
    }
}

@Component("greeting.french")
public class GreetingServiceFrenchImpl implements GreetingService {
	public String sayHello(String name) {
		return "Bonjour " + name;
	}
}
```

With autowired :
```java
	@Autowired
	@Qualifier("greeting.french")
	private GreetingService greeting;
```
AOP only proxy the first implementation (ordered by qualified name), so "greeting.french" bean was not proxied and not feature flipping was available.
An obvious workaround is to rename the default implementation to be the first found but quite ugly... :)

This commit will proxy each implementation of an interface contaning a @Flip method.

Regards,
Gautier