stick to the norm's guaranteed operations on strempos / streamoff (§27.4.3.2)

should fix gcc-3.4-cvs

+ replaced std::streamoff by off_type for consistency.


[SVN r22164]

libs/format

@@ -1 +1 @@
-Subproject commit 86a7a74c832302f58a17c98499535daf32effcd7
+Subproject commit c51a055f920d6bc5bb224c94205cac31144d3e3d