Avoid some Borland bugs by defining operators explicitly rather than

using partially_ordered<...> to generate them.


[SVN r29757]

libs/iterator

@@ -1 +1 @@
-Subproject commit df49ae74e067d978bbc19b86f5b39012fa9140de
+Subproject commit 7a4335065509bb2b9be5f8a467ace1727f3f3346