added a new configure option --with-push, some cleanups, chased code size

* HTMLparser.c Makefile.am configure.in legacy.c parser.c
  parserInternals.c testHTML.c xmllint.c include/libxml/HTMLparser.h
  include/libxml/parser.h include/libxml/parserInternals.h
  include/libxml/xmlversion.h.in: added a new configure
  option --with-push, some cleanups, chased code size anomalies.
  Now a library configured --with-minimum is around 150KB,
  sounds good enough.
Daniel
diff --git a/include/libxml/parser.h b/include/libxml/parser.h
index b76a7c4..11bf648 100644
--- a/include/libxml/parser.h
+++ b/include/libxml/parser.h
@@ -1000,6 +1000,7 @@
 					 const char *name,
 					 void *value);
 
+#ifdef LIBXML_PUSH_ENABLED
 /*
  * Interfaces for the Push mode.
  */
@@ -1014,6 +1015,7 @@
 					 const char *chunk,
 					 int size,
 					 int terminate);
+#endif /* LIBXML_PUSH_ENABLED */
 
 /*
  * Special I/O mode.