Add more languages and normalize language names

This pull request was needed for one of our products. It adds the following languages:

* en-au
* en-us
* id
* ko
* nb-no
* sv
* vi
* zh-hk
* zh-tw

And also normalizes the language names into lowercase and renames 'chs' to its ISO equivalent, 'zh-cn'.

Please feel free to pick and choose as you like.

Note that a couple of languages don't quite work because they require the currency symbol after the number and/or the ordinal symbol before the number. I've marked these with a comment.