Issue #23071: Added missing names to codecs.__all__.  Patch by Martin Panter.

--HG--
branch : 2.7
explicitly close files (closes #23090)

Patch by Brian Kearns.

--HG--
branch : 2.7
extra : amend_source : ecfeb2f46bf29be3763c2cd01bbb60ef4e663c68