enhanced macros to avoid breaking ABI from previous versions. modified to

* genChRanges.py, chvalid.c, include/libxml/chvalid.h,
  include/libxml/parserInternals.h: enhanced macros to avoid
  breaking ABI from previous versions.
* catalog.c, parser.c, tree.c: modified to use IS_* macros
  defined in parserInternals.h.  Makes maintenance much easier.
* testHTML.c, testSAX.c, python/libxml.c: minor fixes to avoid
  compilation warnings
* configuration.in: fixed pushHTML test error; enhanced for
  better devel (me) testing
diff --git a/testSAX.c b/testSAX.c
index edd6d6a..8634b51 100644
--- a/testSAX.c
+++ b/testSAX.c
@@ -82,7 +82,8 @@
     1,
     NULL,
     NULL, /* startElementNs */
-    NULL /* endElementNs */
+    NULL, /* endElementNs */
+    NULL  /* xmlStructuredErrorFunc */
 };
 
 xmlSAXHandlerPtr emptySAXHandler = &emptySAXHandlerStruct;
@@ -694,6 +695,7 @@
     1,
     NULL,
     NULL,
+    NULL,
     NULL
 };
 
@@ -817,7 +819,8 @@
     XML_SAX2_MAGIC,
     NULL,
     startElementNsDebug,
-    endElementNsDebug
+    endElementNsDebug,
+    NULL
 };
 
 xmlSAXHandlerPtr debugSAX2Handler = &debugSAX2HandlerStruct;