bug 365754: finally added DocBook 5.0 DTD and Schema in several formats

Signed-off-by: Florian Thienel <florian@thienel.org>
diff --git a/org.eclipse.vex.docbook/5.0/VERSION b/org.eclipse.vex.docbook/5.0/VERSION
new file mode 100644
index 0000000..819e07a
--- /dev/null
+++ b/org.eclipse.vex.docbook/5.0/VERSION
@@ -0,0 +1 @@
+5.0