First commit of the new Relax-NG validation code, not generally useful

* Makefile.am configure.in relaxng.c include/libxml/relaxng.h:
  First commit of the new Relax-NG validation code, not generally
  useful yet.
* test/relaxng/* result/relaxng/*: current state of the regression
  tests
Daniel
diff --git a/configure.in b/configure.in
index 62a9625..eb67322 100644
--- a/configure.in
+++ b/configure.in
@@ -581,9 +581,9 @@
 
 AC_ARG_WITH(schemas, [  --with-schemas              Add experimental Schemas support (off)])
 if test "$with_schemas" = "yes" ; then
-    echo Enabling Schemas support
+    echo "Enabling Schemas/Relax-NG support"
     WITH_SCHEMAS=1
-    TEST_SCHEMAS="Schemastests"
+    TEST_SCHEMAS="Schemastests Relaxtests"
     with_regexps=yes
 else    
     WITH_SCHEMAS=0