impl_zmq driver. Global CONF object without explicit options registration.

[Ilya Pekelny]

`impl_zmq` driver options registered in `ZmqDriver.__init__` method on a `ConfigOpts` instance passed to the constructor as an argument. But the options used in ZmqProxy, Connection and others classes and functions of the driver with global `CONF`. There is no explicit registration of the options on the global `CONF` object. It can cause unavailability of the options.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/123711

[OpenStack Infra (hudson-openstack)]

Change abandoned by Davanum Srinivas (dims) (<email address hidden>) on branch: master
Review: https://review.openstack.org/123711
Reason: This review is > 12 weeks without comment, and failed Jenkins the last time it was checked. We are abandoning this for now. Feel free to reactivate the review by pressing the restore button and leaving a 'recheck' comment to get fresh test results.