title: How to add @xml:base to my .xml files?
body: <p>I need a stylesheet to convert my docbook xml files so that they now include a xml:base element to my section tags.  How do I go about doing that (since xml:base needs system and node info???)</p>
  
  <p>Input:</p>
  
  <pre><code>&lt;section xmlns="http://docbook.org/ns/docbook" xml:id="voidVisit" version="5"&gt;
  &lt;title&gt;Void&lt;/title&gt;
  
   &lt;section&gt;
    &lt;title&gt;Screenshot&lt;/title&gt;
        &lt;mediaobject&gt;
            &lt;imageobject&gt;
                &lt;imagedata fileref="screenshots/Dialog.png" /&gt;
            &lt;/imageobject&gt;
        &lt;/mediaobject&gt;
   &lt;/section&gt;
  &lt;/section&gt;
  </code></pre>
  
  <p>Output:</p>
  
  <pre><code>      ...
        &lt;section xml:id="void" version="5"
             xml:base="file:/C:/Projects/my/proj/trunk/spec/module/components/void.xml"&gt;
       &lt;title&gt;Void&lt;/title&gt;
       &lt;section&gt;
          &lt;title&gt;Screenshot&lt;/title&gt;
          &lt;mediaobject&gt;
             &lt;imageobject&gt;
                &lt;imagedata fileref="screenshots/Dialog.png"/&gt;
             &lt;/imageobject&gt;
          &lt;/mediaobject&gt;
       &lt;/section&gt;
       ...
  </code></pre>