Introduce error logging when run as a server

[Silvia Pfeiffer]

node server.js

needs some error logging output - otherwise it's unclear what it's doing...or whether it's doing anything at all...

[Damon Oehlman]

Have included some additional debug logging (as of version 0.3) for connections and message writing, simply run the server enabling debug:

DEBUG=rtc* node server.js