Use correct namespace for all children of inserted node too
Use correct namespace for all children of inserted node too

This completes the changes of 077fb0399e82ac12f8258fab47f79791ff0bac07
which set the namespace of the node being inserted into the tree
correctly, but not the namespaces of its children, that also need to be
set to inherit the parent namespace, if they don't already have their
own one, for the same reasons as were mentioned in the other commit
message.

vslavik/xmlwrapp,vadz/xmlwrapp,vadz/xmlwrapp,vslavik/xmlwrapp,vadz/xmlwrapp,vslavik/xmlwrapp