Issue #7449, last part (11): fix many tests if thread support is disabled

 * Use try/except ImportError or test_support.import_module() to import thread
   and threading modules
 * Add @unittest.skipUnless(threading, ...) to testcases using threads
diff --git a/Lib/test/test_threadedtempfile.py b/Lib/test/test_threadedtempfile.py
index 753f388..4aeb711 100644
--- a/Lib/test/test_threadedtempfile.py
+++ b/Lib/test/test_threadedtempfile.py
@@ -16,11 +16,10 @@
 NUM_THREADS = 20
 FILES_PER_THREAD = 50
 
-import thread # If this fails, we can't test this module
-import threading
 import tempfile
 
-from test.test_support import threading_setup, threading_cleanup, run_unittest
+from test.test_support import threading_setup, threading_cleanup, run_unittest, import_module
+threading = import_module('threading')
 import unittest
 import StringIO
 from traceback import print_exc