typed_subpart_iterator(): Fix these to use non-deprecated APIs,
i.e. get_content_maintype() and get_content_subtype().

Also, add True, False for Python 2.2.x where x < 2 compatibility.
diff --git a/Lib/email/_compat22.py b/Lib/email/_compat22.py
index ec2d2f8..e0f72a8 100644
--- a/Lib/email/_compat22.py
+++ b/Lib/email/_compat22.py
@@ -1,7 +1,7 @@
 # Copyright (C) 2002 Python Software Foundation
 # Author: barry@zope.com
 
-"""Module containing compatibility functions for Python 2.1.
+"""Module containing compatibility functions for Python 2.2.
 """
 
 from __future__ import generators
@@ -9,6 +9,13 @@
 from cStringIO import StringIO
 from types import StringTypes
 
+# Python 2.2.x where x < 2 lacks True/False
+try:
+    True, False
+except NameError:
+    True = 1
+    False = 0
+
 
 
 # This function will become a method of the Message class
@@ -58,6 +65,6 @@
     omitted, only the main type is matched.
     """
     for subpart in msg.walk():
-        if subpart.get_main_type('text') == maintype:
-            if subtype is None or subpart.get_subtype('plain') == subtype:
+        if subpart.get_content_maintype() == maintype:
+            if subtype is None or subpart.get_content_subtype() == subtype:
                 yield subpart