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
Please go through all the code and remove explicit new/delete. Use unique_ptr instead.   Or in this case you can even be on the stack and not the heap.