We should add a `console` module that every other modules includes. In the console module we can then filter the messages and display what we need when we want it. e.g. always show errors, but only enable debug logging if desired.

To enable debug logging we could use the same trick the rolodex uses (keep flag in local storage):

https://github.com/openpeer/webrtc.hookflash.me/blob/master/packages/presence/lib/client/client.js#L546-L558
https://github.com/openpeer/webrtc.hookflash.me/blob/master/packages/presence/lib/client/client.js#L635-L637

To change logging settings call this from the browser JS console:

    (function() { require(["rolodex-presence/client"], function (CLIENT) { CLIENT.setDebug(true, ["message", "engine.io"]); }); })()
    (function() { require(["rolodex-presence/client"], function (CLIENT) { CLIENT.setDebug(false); }); })()

And refresh page.

Document logging options in `./demo/README.md` as done here (bottom of page): https://github.com/openpeer/webrtc.hookflash.me

Once this is abstracted we can then easily send errors to a server so we can track client errors centrally.