[Xfce-i18n] A few nb and nb_NO updates for trunk.

[Daniel Nylander]

> nb_NO:
> xfce4-mixer
> xfce4-panel
> xfce4-settings
>
> nb:
> xfconf

What exactly are the differences between nb and nb_NO? (None)
There are just two locales in Norway, nb (bokmål) and nn (nynorsk)
and you should never use any country code.

There are a few exceptions though, zh_TW (Chinese in Taiwan), pt_BR
(Portuguese in Brazil) to name a few.

Daniel
(Swedish)