title: Writing unicode characters with Batik doesn't work
body: <p>I am writing a project with Batik, which is for multi-language image. Therefore I need signs like "sigma" or "alpha". I have to write the character as text - not as a polygon or as a glyph - because it has to be written by my project again.</p>
  
  <p>If I write a unicode character in my SVGDocument it is shown correctly in the debugger, but if I write to SVG there is always a <code>?</code>, or for normal-Letter such as <code>A</code>, <code>?A</code> as a result.</p>
  
  <p>I think is a problem from my writer but I don't know how to fix it. I know that there are some solutions from SVG like using unicode with <code>&amp;#XXX</code> or <code>&amp;sigma;</code> but I can't give the Node that String and it will written in the correct form.</p>
  
  <p>Here is short and hopefully understandable code example:</p>
  
  <pre><code>enter code here
  import java.io.File;
  import java.io.FileWriter;
  import java.net.URI;
  import org.apache.batik.dom.svg.SAXSVGDocumentFactory;
  import org.apache.batik.dom.util.DOMUtilities;
  import org.apache.batik.util.XMLResourceDescriptor;
  import org.w3c.dom.Document;
  import org.w3c.dom.Text;
  public static void main(String args[]) throws Exception
  {
    /* Read Document
     */
    URI source = new URI("file:D:/foo.svg");
    //If there is no Parser:'parser' = null
    String parser = XMLResourceDescriptor.getXMLParserClassName();
    //for right interpretation
    SAXSVGDocumentFactory f = new SAXSVGDocumentFactory(parser);
    String sourceUri = source.toString();
    /* add Textnode
     */
    Document doc = f.createSVGDocument(sourceUri);
    String textWithUni = "\u0041";
    Text textNode = doc.createTextNode(textWithUni);
    doc.appendChild(textNode);
    /*write
     */
    File output = new File("newFoo.svg");
    FileWriter fw = new FileWriter(output);
    DOMUtilities.writeDocument(doc, fw);
    fw.flush();
    fw.close();
  }
  </code></pre>