cleanup, creating a new legacy.c module, made sure make tests ran in

* Makefile.am: cleanup, creating a new legacy.c module,
  made sure make tests ran in reduced conditions
* SAX.c SAX2.c configure.in entities.c globals.c parser.c
  parserInternals.c tree.c valid.c xlink.c xmlIO.c xmlcatalog.c
  xmlmemory.c xpath.c xmlmemory.c include/libxml/xmlversion.h.in:
  increased the modularization, allow to configure out
  validation code and legacy code, added a configuration
  option --with-minimum compiling only the mandatory code
  which then shrink to 200KB.
Daniel
diff --git a/xlink.c b/xlink.c
index d7fc602..4454d17 100644
--- a/xlink.c
+++ b/xlink.c
@@ -11,6 +11,7 @@
 #define IN_LIBXML
 #include "libxml.h"
 
+#ifdef LIBXML_XPTR_ENABLED
 #include <string.h> /* for memset() only */
 #ifdef HAVE_CTYPE_H
 #include <ctype.h>
@@ -177,3 +178,4 @@
     if (role != NULL) xmlFree(role);
     return(ret);
 }
+#endif /* LIBXML_XPTR_ENABLED */