Adds Protobuf + ZeroMQ Networking Example

[daniel-j-h]

Simple Pub-Sub example:

• Publisher polls scans from device, encodes them as Protobuf messages, sends them out.
• Subscribers connect to publisher, decode messages, print to stdout.

I wanted to see how hard it would be to pull this off and at the same time provide additional examples. Maybe it helps.

See #12, #13.

References:

• http://api.zeromq.org/2-1:zmq-cpp

[daniel-j-h]

Merging this. @kent-williams @dcyoung do we still need to think about #13 or can this example be a starting point for users? Do we have to support a networking solution out of the box? (If not please close the issue and reference this Protobuf + ZeroMQ example