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
Does this mean that it is the sender's responsibility to delete the memory AFTER a send? I.e. internally in zmq the memory is copied?

From the same point as from the Readers point. I think the cleanup of memory can be handled within the API to remove any misconceptions of whom responsibility it is to delete the data. 

If ```server.SendData(...)``` would take the same struct as the other side is using then the sender is absolutely 100% sure that the memory is handled within that type. 

In that regard the struct that is now defined only in the receiving side should then be in its own file for use for both the sender and the receiver.