Step one in making the statsd service more modular, by making the config & the logger
something that can be provided to an exported `createServer()` function.

Handle SIGINT as well as SIGTERM for convenient testing.
Have both signal handlers call the same graceful-exit function.
Whitespace; added the temp config file to the ignore list.
Merge pull request #1 from ceejbot/wrappable

make statsd wrappable