Configure server bind address option

ws binds to 0.0.0.0 by default rather than localhost, which exposes the
server to external network devices.

http://git.io/NKtA2Q

Changed the default Chromix server bind address from 0.0.0.0 and added
an optimist option.
Display server.js usage with --help or -h
Merge pull request #3 from chrisdambrosio/fix-bind-server-to-localhost

Change default server bind address