preparing 2.4.18 updated and rebuilt the web site implement the new

* configure.in: preparing 2.4.18
* doc/*: updated and rebuilt the web site
* *.c libxml.h: implement the new IN_LIBXML scheme discussed with
  the Windows and Cygwin maintainers.
* parser.c: humm, changed the way the SAX parser work when
  xmlSubstituteEntitiesDefault(1) is set, it will then
  do the entity registration and loading by itself in case the
  user provided SAX getEntity() returns NULL.
* testSAX.c: added --noent to test the behaviour.
Daniel
diff --git a/nanoftp.c b/nanoftp.c
index 875e54a..03d6888 100644
--- a/nanoftp.c
+++ b/nanoftp.c
@@ -16,6 +16,7 @@
 #define NEED_SOCKETS
 #endif /* TESTING */
 
+#define IN_LIBXML
 #include "libxml.h"
 
 #ifdef LIBXML_FTP_ENABLED