preparing release 2.5.7 updated and rebuilt the docs fixed the script

* NEWS configure.in: preparing release 2.5.7
* doc/*: updated and rebuilt the docs
* doc/apibuild.py: fixed the script
Daniel
diff --git a/NEWS b/NEWS
index 6db6ea5..35af519 100644
--- a/NEWS
+++ b/NEWS
@@ -18,6 +18,26 @@
 
 
 
+2.5.7: Apr 25 2003:
+   - Relax-NG: Compiling to regexp and streaming validation on top of the
+    xmlReader interface, added to xmllint --stream
+   - xmlReader: Expand(), Next() and DOM access glue, bug fixes
+   - Support for large files: RGN validated a 4.5GB instance
+   - Thread support is now configured in by default
+   - Fixes: update of the Trio code (Bjorn), WXS Date and Duration fixes
+    (Charles Bozeman), DTD and namespaces (Brent Hendricks), HTML push parser
+    and zero bytes handling, some missing Windows file path conversions,
+    behaviour of the parser and validator in the presence of "out of memory"
+    error conditions 
+   - extended the API to be able to plug a garbage collecting memory
+    allocator, added xmlMallocAtomic() and modified the allocations
+    accordingly.
+   - Performances: removed excessive malloc() calls, speedup of the push and
+    xmlReader interfaces, removed excessive thread locking
+   - Documentation: man page (John Fleck), xmlReader documentation
+   - Python: adding binding for xmlCatalogAddLocal (Brent M Hendricks)
+
+
 2.5.6: Apr 1 2003:
    - Fixed W3C XML Schemas datatype, should be compliant now except for
     binHex and base64 which are not supported yet.