serious cleanup of the spec file and associated changes in the Makefiles.

* Makefile.am config.h.in libxml.spec.in doc/Makefile.am:
  serious cleanup of the spec file and associated changes
  in the Makefiles.
* valid.c: try to remove some warnings on x86_64
Daniel
diff --git a/Makefile.am b/Makefile.am
index b56c815..36afdd3 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -707,7 +707,7 @@
 #
 # Instll the tests program sources as examples 
 #
-BASE_DIR=@HTML_DIR@
+BASE_DIR=$(datadir)/doc
 DOC_MODULE=libxml2-$(VERSION)
 EXAMPLES_DIR=$(BASE_DIR)/$(DOC_MODULE)/examples