added missing dependencies to fix the failing unit tests
diff --git a/org.eclipse.vex.core/META-INF/MANIFEST.MF b/org.eclipse.vex.core/META-INF/MANIFEST.MF
index 7d83972..9b34020 100644
--- a/org.eclipse.vex.core/META-INF/MANIFEST.MF
+++ b/org.eclipse.vex.core/META-INF/MANIFEST.MF
@@ -7,7 +7,9 @@
 Require-Bundle: org.eclipse.core.runtime;bundle-version="[3.4.0,4.0.0)",
  org.eclipse.ui;bundle-version="[3.4.0,4.0.0)",
  org.eclipse.wst.xml.core;bundle-version="[1.1.0,2.0.0)",
+ org.eclipse.wst.dtd.core;bundle-version="[1.1.0,2.0.0)",
  org.eclipse.wst.common.uriresolver;bundle-version="[1.1.0,2.0.0)",
+ org.eclipse.wst.xsd.core;bundle-version="[1.1.0,2.0.0)",
  org.w3c.css.sac;bundle-version="[1.3.0,2.0.0)",
  org.apache.batik.css;bundle-version="1.7.0",
  org.apache.batik.util;bundle-version="1.7.0"