Debug messages in config

[mhuretski]

Hi,

Currently there's no way to turn off debug messages on local machine. It's very convenient to have them during debugging, but when everything is set up, there's no point to have them in console both on server and client.

This is non-breaking change that adds ability to turn them off.

If it's not a good fit for your vision, could you add ability to turn them off the way you see it?