file io

- We still need to come up with a naming metaphor for this!
- it is a pipeline communication to stream a file from a server to a client.
- It follows a model similar to: http://zguide.zeromq.org/c:fileio3
I asked earlier but my question got removed when the formatting changes happened. 

Is zmq cleaning up automatically the ipc files? Or must there be manually cleanup of ipc files?