add methods that verify types

[renanreismartins]

Add a method that verifies if a Object is a collection.
Add a method that verifies if a Object is a primitive.
And a method that verifies the type of object.

Something like the methods isCollection(Type type), getActualType(Type genericType)
found here: https://github.com/caelum/vraptor/blob/master/vraptor-core/src/main/java/br/com/caelum/vraptor/serialization/xstream/Serializee.java

and isPrimitive(Class<?> type)
found here: https://github.com/caelum/vraptor/blob/master/vraptor-core/src/main/java/br/com/caelum/vraptor/serialization/xstream/VRaptorClassMapper.java

What do you think about this?