- 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/encodings/punycode.py b/Lib/encodings/punycode.py
index d97200f..0e4aa0b 100644
--- a/Lib/encodings/punycode.py
+++ b/Lib/encodings/punycode.py
@@ -17,8 +17,7 @@
             base.append(c)
         else:
             extended[c] = 1
-    extended = extended.keys()
-    extended.sort()
+    extended = sorted(extended.keys())
     return "".join(base).encode("ascii"),extended
 
 def selective_len(str, max):