Added support for lists to serialize child element with tags based on their class name

Added a way for objects being in a List to be serialised with a tag name that use the object class name.  

For example, here below is a Car object that contains a List property named childrens. In this list are a Motor and Wheel objects. By setting path='',  the serialised doc will be:

<Car>
 <Motor/>
 <Wheel/>
</Car>


@Mappings({
	
	@Mapping( value="childrens", path="" ),
})

public interface CarXmlWriter extends XmlWriter<Car> {

}