Inheritance of "orderable" attribute for node types

[Christoph Kiehl]

Hi,

we just discovered, that the "orderable" attribute of node types is not 
inherited from supertypes. NodeTypeImpl.hasOrderableChildNodes() just calls 
NodeTypeDef.hasOrderableChildNodes() instead of using the EffectiveNodeType to 
determine if a node type allows orderable child nodes.
The specification does not define how this should be handled (6.7.8 Inheritance 
Among Node Types), but was there any reason not to use EffectiveNodeType?

Cheers,
Christoph