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
atoi will cause undefined behavior if input is not well formed. Please use one of these instead: http://en.cppreference.com/w/cpp/string/basic_string/stol