Swap out RabbitMQ for ZeroMQ

Needs better round-robin dispatching for tasks, but fine for now
Use zeromq for OOB messages from Rserve
Redirect stderr to stdout
Properly return the results (don't be an idiot)
Make server responsible for storage

- worker pushes results
- server merges the results with the statuses
- statuses now also in mongodb (instead of Software Transactional Memory (i.e. atom))
Use router (load-balancing) pattern instead of push-pull
Fixes to closing of listener socket to R
Less slow test script
Use correct library for jzmq
[experimental] add TTL to statuses collection
Define a common package

- Currently includes utilities for zeromq
Dispatch to workers based on method
Set timeout on Thread/join for RServe updates
More slow slow.R test script
Fix creation of mongodb collection if already exists
Do not run nrepl in development
Cleanup
Ping-Pong between workers and server
Use ping-pong with reconnect consumer

- Takes 100% cpu on connection lost ...
Start with EXTREMELY UNFINISHED rewrite

- pushing because I'm switching machines