- PEP 3106: dict.iterkeys(), .iteritems(), .itervalues() are now gone;
  and .keys(), .items(), .values() return dict views.

The dict views aren't fully functional yet; in particular, they can't
be compared to sets yet.  but they are useful as "iterator wells".

There are still 27 failing unit tests; I expect that many of these
have fairly trivial fixes, but there are so many, I could use help.
diff --git a/Lib/trace.py b/Lib/trace.py
index b2ec557..0f89c15 100644
--- a/Lib/trace.py
+++ b/Lib/trace.py
@@ -282,7 +282,7 @@
         # accumulate summary info, if needed
         sums = {}
 
-        for filename, count in per_file.iteritems():
+        for filename, count in per_file.items():
             # skip some "files" we don't care about...
             if filename == "<string>":
                 continue