Udp support for  2.x-maintenance

More: #9 
This probably shouldn't be `static`. It doesn't look like `StatsDClient` is thread-safe, as it creates a single socket connection internally: http://grepcode.com/file/repo1.maven.org/maven2/com.timgroup/java-statsd-client/1.0.1/com/timgroup/statsd/StatsDClient.java. There may be multiple reporters running and we don't want them to be concurrently writing to the socket and corrupting the stream.