Add logstash support for Console transport

We, for example, use supervisor to take the stdout of all our processes and merge them into a huge logstash-log blob.
Logstash (at least in our version) expects each log event to be in a single line, and the `(obj, null, **2**)` forces the output to be pretty-printed (and broken into several lines). I don't know if this is the most ideal solution, but it worked.