Merge with 3.3

Lib/test/test_idle.py

-# Skip test if tkinter wasn't built or idlelib was deleted.
+# Skip test if _tkinter or _thread wasn't built or idlelib was deleted.
 from test.support import import_module
-import_module('tkinter')  # discard return
-itdir = import_module('idlelib.idle_test')
+import_module('tkinter')
+import_module('threading')  # imported by PyShell, imports _thread
+idletest = import_module('idlelib.idle_test')
 
-# Without test_main present, regrtest.runtest_inner (line1219)
-# imitates unittest.main by calling
-# unittest.TestLoader().loadTestsFromModule(this_module)
-# which look for load_tests and uses it if found.
-load_tests = itdir.load_tests
+# Without test_main present, regrtest.runtest_inner (line1219) calls
+# unittest.TestLoader().loadTestsFromModule(this_module) which calls
+# load_tests() if it finds it. (Unittest.main does the same.)
+load_tests = idletest.load_tests
 
 if __name__ == '__main__':
     import unittest