make ZeroMQIPC.py work with eventlet 0.9.17 and beyond

The zmq.Poller implementation for eventlet no longer works with the totally
revamped zmq support strategy in eventlet 0.9.17 and beyond.

This code drops the zmq.Poller patch in favor of eventlet specific code in ZeroMQIPC.py.

Change-Id: I3f0a927359d23b1a61d1cb71c6abd042872536b3
Merge pull request #5 from mzero/joe-wip-zeromq

Make ZeroMQIPC.py work with eventlet 0.9.17 and beyond