changing xml schema definitions ?

[Tom Zeller]

I think I would like to change an xml schema definition, which should
be backwards compatible, and I am wondering if that is okay.

While porting the spring wiring for the scripted attribute definition,
I want to change

 <attribute name="language" type="string">

to

 <attribute name="language" type="string" default="javascript">

so that the default value of the language attribute is controlled by
the xsd rather than the bean definition parser. Thus the following can
be removed from the bean definition parser, to keep it simpler :

String scriptLanguage = "javascript";
if (pluginConfig.hasAttributeNS(null, "language")) {
  scriptLanguage = pluginConfig.getAttributeNS(null, "language");
}

Not sure how we version those xsd's though. I guess that is my real
question, how do we version the xsd's ?