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
if (received_counter != gExpectedPacketsToReceive) {
   ADD_FAILURE << "some explaining text"  << receive_counter << ": " << gExpectedPacketsToReceive;
}
return nullptr