Change in locale for Norwegian bokmål

Hi.

The iso language code for Norwegian bokmål has been changed from no to
nb and it would be nice to get that change reflected in a2ps too. Please
change the filename from no.po to nb.po and also the entry in
ALL_LINGUAS or po/LINGUAS depending on which is being used.

I've put the original contributor on Cc:

Btw, the list of languages here:
http://www.inf.enst.fr/~demaille/a2ps/po-2.html#Norvegian

spells Nor*w*egian wrong :-)

Cheers
Kjartan