Made sure that iterator_facade's nested ``::pointer`` type is always

the same as what's returned from operator->.  For input iterators,
that wasn't always the case (see operator_arrow_proxy).

Fixes #1019.


[SVN r57989]

libs/iterator

@@ -1 +1 @@
-Subproject commit d11c7a3ec4d34cc16aecb246d636528948702ad5
+Subproject commit 4c60e26bf8cdf6602375eaab23a95f4849333fd6