Register Japanese MIME aliases

[Loewis]

With this patch, the common MIME names for Japanese
encodings become available when the Japanese codecs are
installed.

The precise location of this code in mailman does not
matter; it should be executed before any codec is accessed.

[http://sourceforge.net/tracker/index.php?func=detail&aid=538185&group_id=103&atid=300103]

[Loewis (loewis)]

The second version of this patch avoids importing existing
codecs merely to establish their presence.

[Barry Warsaw (barry)]

I'll add this to Defaults.py.in which should get imported
early enough in any process. Is this patch safe in Pythons
2.1, 2.2 and 2.3?

[Loewis (loewis)]

Yes, it should work with any version since 2.0; all it
requires is that encodings.aliases.aliases exists and is a
dictionary.

[Barry Warsaw (barry)]

Cool, thanks. Accepted and closing.