Bug 1046236 — Log call state modification with the websocket.

https://bugzilla.mozilla.org/show_bug.cgi?id=1046236
Based on #185.
Can we add the uid of the caller and the callee on this log line? We'd be using them for the recurring counts. If they are not available, we can associate success/failure with the uid of the request.summary line, but it would be helpful/efficient if they were logged here.