Changed the new xmlRead/xmlCtxtRead APIs to have an extra base URL

* parser.c xmllint.c doc/libxml2-api.xml include/libxml/parser.h:
  Changed the new xmlRead/xmlCtxtRead APIs to have an extra
  base URL parameter when not loading from a file or URL.
Daniel
diff --git a/win32/libxml2.def.src b/win32/libxml2.def.src
index 7710eb0..247ffdf 100644
--- a/win32/libxml2.def.src
+++ b/win32/libxml2.def.src
@@ -673,6 +673,7 @@
 xmlDictLookup
 xmlDictOwns
 xmlDictQLookup
+xmlDictReference
 xmlDictSize
 xmlDocCopyNode
 xmlDocDump