check all the namespace support was actually correct based on tutorial

* test/relaxng/* result/relaxng/*: check all the namespace support
  was actually correct based on tutorial section 10.
Daniel
diff --git a/test/relaxng/tutor10_2_3.xml b/test/relaxng/tutor10_2_3.xml
new file mode 100644
index 0000000..898193d
--- /dev/null
+++ b/test/relaxng/tutor10_2_3.xml
@@ -0,0 +1 @@
+<foo xmlns="http://www.example.com"/>