AssociationPolicy

Fall back to @Behaviour classnames if none provided on @AssociationPolicy.
The test on the class count specified "> 1". Was there a specific reason to have at least 2 classes ?

The use case is:
```java
@Behaviour("cm:content")
public class MyPolicy {
	@AssociationPolicy(association = "cm:contains")
	@Override
	public void onCreateChildAssociation(final ChildAssociationRef childAssocRef, final boolean isNewNode) {}
}
```