This is a proof-of-concept that uses ZeroMQ as transport.
It uses a star topology as opposed to the native mesh network.

Package ZMQ must be installed. All workers only run on localhost.

All Julia nodes only connect to a "broker" process that listens on known ports
8100 and 8101 via ZMQ sockets.


All commands must be run from `examples/clustermanager/0mq` directory

First, start the broker. In a new console type:
    julia broker.jl

This does not return.

Next, start a Julia REPL and type:
    include("ZMQCM.jl")
    ZMQCM.start_master(4) # start with four workers


Alternatively, head.jl, a test script could be run. It just launches the requested number of workers,
executes a simple command on all of them and exits.
    julia head.jl 4

NOTE: As stated this is a proof-of-concept. A real Julia cluster using ZMQ will probably use
different ZMQ socket types and optimize the transport.
