Bug#361048: locales: locale settings lost after upgrade

[Denis Barbier <barbier@linuxfr.org>]

[Steve Langasek]
> Right.  The locales package still shouldn't be trying to "clean up" this
> config file, because two wrong writes to the file don't make a right write.
> :)

I understand, and -7 has been uploaded yesterday with a slightly different
fix: /etc/environment is not modified at all in postinst, but in config,
default locale is read from /etc/environment when upgrading from
locales < 2.3.6-5 and from /etc/default/locale otherwise.
A NEWS.Debian file has also been added, but I realize that its wording may
be improved to tell that some applications may still read values from
/etc/environment, will fix it later.
2.3.6-7 is waiting in the NEW queue.

Denis