Merge pull request #7 from selsky/nothreads

Additional ZMQ 3.x compatibility fixes.
Fixed a compile warning in the MQ broker.
Run the command/state poll inside the Nagios sleeps instead of at beginnings of timed events.
The timeval/timespec macros aren't available everywhere. This expands them and slightly simplifies the code.
Adding additional ZeroMQ 3.x options to mqbroker.