hack based on Arjan van de Ven suggestion to reduce ELF footprint and

* elfgcchack.h doc/elfgcchack.xsl libxml.h: hack based on Arjan van de
  Ven suggestion to reduce ELF footprint and generated code. Based on
  aliasing of libraries function to generate direct call instead of
  indirect ones
* doc/libxml2-api.xml doc/Makefile.am doc/apibuild.py: added automatic
  generation of elfgcchack.h based on the API description, extended
  the API description to show the conditionals configuration flags
  required for symbols.
* nanohttp.c parser.c xmlsave.c include/libxml/*.h: lot of cleanup
* doc/*: regenerated the docs.
Daniel
diff --git a/Makefile.am b/Makefile.am
index fb26202..0e42e76 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -976,7 +976,7 @@
              example/Makefile.am example/gjobread.c example/gjobs.xml \
 	     $(man_MANS) libxml-2.0.pc.in libxml-2.0-uninstalled.pc.in \
 	     trionan.c trionan.h triostr.c triostr.h trio.c trio.h \
-	     triop.h triodef.h libxml.h \
+	     triop.h triodef.h libxml.h elfgcchack.h \
 	     testThreadsWin32.c genUnicode.py TODO_SCHEMAS \
 	     dbgen.pl dbgenattr.pl