Implemented endpoint communication with ZeroMQ.
Updated README.
Added support for client-to-host communication.
Code refactorings and fixed client-to-server messaging.
Changed field names.
Implemented document support.
Added MessageType support.
Fixed the bug where the host was receiving messages from only one client.
Added thread pool termination to ZmqChannelListener.
Updated AbstractChannelListener to allocate a fixed thread pool that scales to the number of available CPUs.
Merge pull request #1 from tylertreat/master

Foundational code