xmlCleanNamespaces: Remove redundant namespaces on an XML document
Description
This is a convenience function that removes redundant
repeated namespace definitions in an XML node.
It removes namespace definitions in nodes
where an ancestor node also has that definition.
It does not remove unused namespace definitions.
the name of a file to which to write the resulting XML
document, or an empty character vector or logical value FALSE
to avoid writing the new document.
Value
If the new document is written to a file, the name of the file is
returned.
Otherwise, the new parsed XML document is returned.