Get rid of a bunch more has_key() uses.  We *really* need a tool for this.
test_aepack now passes.  IDLE still needs to be converted (among others).
diff --git a/Lib/plat-mac/aepack.py b/Lib/plat-mac/aepack.py
index 529a0a4..f16171b 100644
--- a/Lib/plat-mac/aepack.py
+++ b/Lib/plat-mac/aepack.py
@@ -129,7 +129,7 @@
     """Unpack an AE descriptor to a python object"""
     t = desc.type
 
-    if unpacker_coercions.has_key(t):
+    if t in unpacker_coercions:
         desc = desc.AECoerceDesc(unpacker_coercions[t])
         t = desc.type # This is a guess by Jack....