clean up representer injecting.
adding a test for :parse_strategy and XML, which was supposed to fail.
make XML::CollectionBinding#deserialize with parse_strategy work. still ugly, thou.
move CollectionDeserializer to Binding so it is in line with ObjectDeserializer.
get rid of #deserialize_node by introducing #content_for. this might look more redundant but can easily replaced by moving this behaviour into Node or a ScalarDecorator.
cleanup Binding.
moving prepare and .from_hash (deserialization) into the ObjectDeserializer just to see the dependencies.
we don't need Prepare#deserialize anymore.