Feature/langloc

This will return a client.json file based on user preference.
It will work from most preferred to least, to "en" as the default.
It also presumes all pathnames are in lower case (because LCD)

@kitcambridge, @nchapman r?
I wrote a quick tester to see and basically, the way I first did this is the slowest (~3.5us for 10K iterations of random text). Regex wasn't much better. The most optimal way was direct range checks. (~2.3us) There are ways I can format them to be more readable, so going with that.