Install language packs for system

Ubiquity language selection and/or preseed will set the system locale
Karoshi Client translation support

l10n/init-translations generates l10n/karoshi-client.pot and all supported
language .po files. l10n/gtranslate can run these files through Google
Translate, or the .po files can be translated by a human.

On installation, the .po files are converted into .mo files and put into the
correct places.