[silva-dev] Silva XML import/export machinery

[eric casteleijn]

> The old style import/export is triggered when the user selects "export to Silva xml (.xml)" and consists of implementing the 'to_xml()' method on the custom content object (for the export) and the xml_import_handler() method for the import.

Yes, this button is actually gone in Silva 1.6, since the exported xml 
wasn't the same as the new exported xml. It should have been removed 
long ago. So there isn't actually a great need to implement the old 
style export, unless you are using docma, which depends on it.

eric