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?
Doesn't Go support Regular Expressions? This seems like it may be more readable as a RegExp like /[\w.-;,]/i (or whatever the exact syntax would be). 

https://github.com/StefanSchroeder/Golang-Regex-Tutorial/blob/master/01-chapter1.markdown (wow, even supports Posix char classes and `[[:alnum:]]`, classy!)