- 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/filecmp.py b/Lib/filecmp.py
index dda2272..9c0ce5a 100644
--- a/Lib/filecmp.py
+++ b/Lib/filecmp.py
@@ -187,7 +187,7 @@
 
     def phase4_closure(self): # Recursively call phase4() on subdirectories
         self.phase4()
-        for sd in self.subdirs.itervalues():
+        for sd in self.subdirs.values():
             sd.phase4_closure()
 
     def report(self): # Print a report on the differences between a and b
@@ -217,13 +217,13 @@
 
     def report_partial_closure(self): # Print reports on self and on subdirs
         self.report()
-        for sd in self.subdirs.itervalues():
+        for sd in self.subdirs.values():
             print()
             sd.report()
 
     def report_full_closure(self): # Report on self and subdirs recursively
         self.report()
-        for sd in self.subdirs.itervalues():
+        for sd in self.subdirs.values():
             print()
             sd.report_full_closure()