[i18n] Updated nb_NO IMP4 translation

[Torbjorn Grindhaug]

I've updated the IMP4 and Kronolith nb_NO translations.
I got a reply from the previous IMP4-translator, Øystein Steimler,
that he's ok with the IMP-translation.
The updates can be found at:

http://grindhaug.com/imp/nb_NO.po
http://grindhaug.com/kronolith/nb_NO.po

I also hope to soon update this locale on some of the other modules, too.

Torbjorn