Standardize on test.test_support.run_unittest() (as opposed to a mix of run_unittest() and run_suite()). Also, add functionality to run_unittest() that admits usage of unittest.TestLoader.loadTestsFromModule().

- gbk and gb18030 codec now handle U+30FB KATAKANA MIDDLE DOT correctly.
- iso2022_jp_2 codec now encodes into G0 for KS X 1001, GB2312
  codepoints to conform the standard.
- iso2022_jp_3 and iso2022_jp_2004 codec can encode JIS X 2013:2
  codepoints now.

anymore.

and installed layouts to make maintenance simple and easy.  And it
also adds four new codecs; big5hkscs, euc-jis-2004, shift-jis-2004
and iso2022-jp-2004.

Several style fixes are suggested by Martin v. Loewis and
Marc-Andre Lemburg. Thanks!