Use XSD

Author: garydgregory

src/changes/changes.xml

@@ -39,7 +39,9 @@ then tweak the source formatting if necessary and regenerate, then commit
 The <action> type attribute can be add,update,fix,remove.
 -->
 
-<document>
+<document xmlns="http://maven.apache.org/changes/1.0.0"
+          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+          xsi:schemaLocation="http://maven.apache.org/changes/1.0.0 http://maven.apache.org/xsd/changes-1.0.0.xsd">
   <properties>
     <title>Apache Commons IO Release Notes</title>
   </properties>