Add CJK codecs support as discussed on python-dev. (SF #873597)

Several style fixes are suggested by Martin v. Loewis and
Marc-Andre Lemburg. Thanks!
diff --git a/Lib/test/test_codecmaps_tw.py b/Lib/test/test_codecmaps_tw.py
new file mode 100644
index 0000000..9b28fef
--- /dev/null
+++ b/Lib/test/test_codecmaps_tw.py
@@ -0,0 +1,39 @@
+#!/usr/bin/env python
+#
+# test_codecmaps_tw.py
+#   Codec mapping tests for ROC encodings
+#
+# $CJKCodecs: test_codecmaps_tw.py,v 1.2 2004/01/17 12:47:19 perky Exp $
+
+from test import test_support
+from test import test_multibytecodec_support
+import unittest
+
+class TestBIG5Map(test_multibytecodec_support.TestBase_Mapping,
+                  unittest.TestCase):
+    encoding = 'big5'
+    mapfilename = 'BIG5.TXT'
+    mapfileurl = 'http://www.unicode.org/Public/MAPPINGS/OBSOLETE/' \
+                 'EASTASIA/OTHER/BIG5.TXT'
+
+class TestCP950Map(test_multibytecodec_support.TestBase_Mapping,
+                   unittest.TestCase):
+    encoding = 'cp950'
+    mapfilename = 'CP950.TXT'
+    mapfileurl = 'http://www.unicode.org/Public/MAPPINGS/VENDORS/MICSFT/' \
+                 'WINDOWS/CP950.TXT'
+    pass_enctest = [
+        ('\xa2\xcc', u'\u5341'),
+        ('\xa2\xce', u'\u5345'),
+    ]
+
+def test_main():
+    suite = unittest.TestSuite()
+    suite.addTest(unittest.makeSuite(TestBIG5Map))
+    suite.addTest(unittest.makeSuite(TestCP950Map))
+    test_support.run_suite(suite)
+
+test_multibytecodec_support.register_skip_expected(TestBIG5Map, TestCP950Map)
+if __name__ == "__main__":
+    test_main()
+