Rewrite the internal daemon socket protocol.

This should be a purely internal change, but if you have been using lorri internal stream-events in your scripts, the json output might have changed. Since the command is internal and not yet stable, not much time was spent keeping it compatible, so beware.

The --socket-address command to lorri ping was removed for now, since only having it for this command doesn’t make much sense, it looks like it was originally introduced for debugging purposes. In the long run we could add a LORRI_SOCKET environment variable.