cleanup document type handling and doctypes in docbook plugin

Change-Id: Ieae7693a39f1837cba4b822e316c08f6b3dd3864
Signed-off-by: Carsten Hiesserich <carsten.hie@gmail.com>
diff --git a/org.eclipse.vex.core.tests/plugin.xml b/org.eclipse.vex.core.tests/plugin.xml
index a23c416..17a8faa 100644
--- a/org.eclipse.vex.core.tests/plugin.xml
+++ b/org.eclipse.vex.core.tests/plugin.xml
@@ -13,10 +13,18 @@
                name="http://www.eclipse.org/vex/test/content"

                uri="testResources/content.xsd">

          </uri>

+         <system

+               systemId="http://www.eclipse.org/vex/test/content.xsd"

+               uri="testResources/content.xsd">

+         </system>

          <public

                publicId="-//Eclipse Foundation//DTD Vex Test//EN"

                uri="testResources/test1.dtd">

          </public>

+       <uri

+             name="urn:org:eclipse:vex:styles:test:test.css"

+             uri="testResources/test.css">

+       </uri>

       </catalogContribution>

    </extension>