International support for statsd

When running the client on my PC I've noticed that the delimiter for non even sample rates were wrong.

I live in Denmark and the default delimiter is a command (,) not a period (.) as it is in US. The danish formatting of a command string would therefore be something like: counter:1|c|@0,1 - notice the different delimiter.

It's a small change to enable the invariant culture formatting to the commands string.