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
See my comment in the end regarding simplifying the API.  We can discuss the API tomorrow.  My thought is that it can be simplified and easier to use.  Below I put an example of simplification to show what I mean.

~~size_t FileRecv::Monitor(){...}~~
~~GetData()~~
~~GetSize()~~

replaced by:
struct ZtreamData{uint8_t*, size_t size}
typedef std::unique_ptr<ZtreamData, DeleteFunc>   ZtreamDataPtr;

ZtreamerResult  Ztreamer::Receive(ZtreamDataPtr) {.... }

Usage would then be something in the style of 
while(ZtreamerResult::Continues == in.Receive(raw)){
  ... Handle the data in raw
}