Added XML object to what-changed.

Picking off low hanging fruit, before attacking the big, ugly stuff.

Signed-off-by: Dave Shanley <dave@quobix.com>

datamodel/low/v3/constants.go

@@ -47,4 +47,8 @@ const (
 	VersionLabel           = "version"
 	LicenseLabel           = "license"
 	ContactLabel           = "contact"
+	NamespaceLabel         = "namespace"
+	PrefixLabel            = "prefix"
+	AttributeLabel         = "attribute"
+	WrappedLabel           = "wrapped"
 )