Various patches and bug fixes, and XInclude progresses:

- nanohttp.[ch]: applied Wayne Davison patches to access
  the WWW-Authorization header.
- parser.c: Closed Bug#30847: Problems when switching encoding
  in short files by applying Simon Berg's patch.
- valid.c: fixed a validation problem
- hash.c parser.h parserInternals.h testHTML.c testSAX.c tree.h
  xmlerror.h xmlmemory.h xmlversion.h.in: applied a DLL patch from
  Wayne Davison
- xpointer.[ch]: added first version of xmlXPtrBuildNodeList()
  need to be extended to non full nodes selections.
- xinclude.c: starts to work decently
Daniel

testHTML.c

@@ -8,6 +8,7 @@
 
 #ifdef WIN32
 #include "win32config.h"
+#undef LIBXML_DLL_IMPORT
 #else
 #include "config.h"
 #endif