Add support for specifying IP Address to listen on

This patch adds a listen parameter to the config.yml and to the config options.
Useful if you only want to listen on one IP address.
change address short option so as not to conflict with logging option
Merge pull request #407 from mjc/master

Add support for specifying IP Address to listen on
Attempted fix to #389 (and many others)

Sounds like the latest CFPropertyList gem (2.2.0) breaks SiriProxy. I adjusted the runtime dependency to use 2.1.2 instead (which should work).

I'm away from home so I don't actually have the ability to test the fix, but hopefully someone can test it.