Metrics 3.1.0 update and suffixing possibility for metrics name

[htimur]

In our architecture, we run statsd on each server, and they all send to a central graphite server and it's pretty useful to have the possibility to suffix the metric name with current host name.

This pull request allows you to send metrics like "some.metric.name.with.suffix.%s" if you configure the suffix as "host1" it'll be replaced as "some.metric.name.with.suffix.host1".

[mkeesey]

This looks pretty reasonable - I'm sorry I haven't had time to look at this previously, and I'm not sure if folks at ReadyTalk are going to have time to look at this in the future.

Sorry about that.