title: XML Catalog rewriteSystem with Xerces2j doesn't work
body: <p>I tried to redirect my DTD just from the old to a new location using Xerces2J with Saxon and an XML Catalog. But Always I've got this error:</p>
  
  <pre><code>Parse catalog: C:/temp/catalog.xml
  Loading catalog: C:/temp/catalog.xml
  Default BASE: file:C:/temp/catalog.xml
  override: no
  OVERRIDE: no
  rewriteURI: file:///zfhpsys
      file:///X:/z186485_hpsys_pa_cr113019_revision_tracking/zfhpsys
  REWRITE_URI: file:///zfhpsys
      file:/X:/z186485_hpsys_pa_cr113019_revision_tracking/zfhpsys
  rewriteURI: /
      file:///X:/z186485_hpsys_pa_cr113019_revision_tracking/
  REWRITE_URI: /
      file:/X:/z186485_hpsys_pa_cr113019_revision_tracking/
  rewriteSystem: /zfhpsys
      file:///X:/z186485_hpsys_pa_cr113019_revision_tracking/zfhpsys
  REWRITE_SYSTEM: /zfhpsys
      file:/X:/z186485_hpsys_pa_cr113019_revision_tracking/zfhpsys
  Failure reading file:
  /X:/z186485_hpsys_pa_cr113019_revision_tracking/zfhpsys/tool_int/software_doku/dokusystem/serna/plugin/software_doku/example/revisons2.xml: 
  \zfhpsys\tool_int\software_doku\dokusystem\epic\custom\doctypes\XMLBlock\XMLBlock.dtd 
  (File not found)
  </code></pre>
  
  <p>So the substition doesn't work.
  This is my catalog.xml:</p>
  
  <pre><code>&lt;?xml version='1.0' encoding='UTF-8'?&gt;
  &lt;!DOCTYPE catalog PUBLIC "-//OASIS//DTD XML Catalogs V1.0//EN" "http://www.oasis-    open.org/committees/entity/release/1.0/catalog.dtd"&gt;
  &lt;catalog xmlns="urn:oasis:names:tc:entity:xmlns:xml:catalog"  prefer="system"&gt;  
   &lt;rewriteSystem systemIdStartString="/zfhpsys"    rewritePrefix="file:///X:/z186485_hpsys_pa_cr113019_revision_tracking/zfhpsys"/&gt;
   &lt;rewriteURI    uriStartString="file:///zfhpsys"  rewritePrefix="file:///X:/z186485_hpsys_pa_cr113019_revision_tracking/zfhpsys"/&gt; 
   &lt;rewriteURI    uriStartString="/"                rewritePrefix="file:///X:/z186485_hpsys_pa_cr113019_revision_tracking/"/&gt;
  &lt;/catalog&gt;
  </code></pre>
  
  <p>And this is the XML-File:</p>
  
  <pre><code>&lt;?xml version='1.0' encoding='UTF-8'?&gt;
  &lt;!DOCTYPE XMLBlock SYSTEM "/zfhpsys/tool_int/software_doku/dokusystem/epic/custom/doctypes/XMLBlock/XMLBlock.dtd" [
  &lt;!ENTITY csv SYSTEM "/zfhpsys/tool_int/software_doku/dokusystem/serna/plugin/software_doku/example/sample_config.csv"&gt;]&gt;
  &lt;XMLBlock DocID="bla"&gt;
    &lt;Title if="(TEST)"&gt;Doc Name&lt;/Title&gt;
    &lt;Description&gt;
      &lt;Heading&gt;[1.1] EDIT description&lt;/Heading&gt;
      &lt;Content if="(CANCEL_BUTTON)"&gt;Er hörte leise Schritte hinter sich. &lt;/Content&gt;
    &lt;/Description&gt;
  &lt;/XMLBlock&gt;
  </code></pre>
  
  <p>At least the CatalogManager.properties:</p>
  
  <pre><code> catalogs=C:/temp/catalog.xml
   relative-catalogs=false
   static-catalog=no
   catalog-class-name=org.apache.xml.resolver.Resolver
   verbosity=10
  </code></pre>
  
  <p>So the log tells me that the catalog has been read, but the SYSTEM has not been replaced. 
  What did I wrong?</p>
  
  <p>Best regards</p>
  
  <p>Markus</p>