decode_rfc2231(): We need to urllib.unquote() the value even if the

charset and language fields are not present, e.g. as in:

    title*0="This%20is%20encoded"

Lib/email/Utils.py

@@ -280,7 +280,7 @@ def decode_rfc2231(s):
     import urllib
     parts = s.split("'", 2)
     if len(parts) == 1:
-        return None, None, s
+        return None, None, urllib.unquote(s)
     charset, language, s = parts
     return charset, language, urllib.unquote(s)