hubs: defang after remove; related to second simultaneous read issue

https://github.com/eventlet/eventlet/issues/94

We have to defang the listener after removing it from the hub

Otherwise we never actaully remove it from the hub and get a return of the
second simultanous read.

This should fix this issue.

Turn off __builtin__ monkey patching by default

The reason is that eventlet.greenio.GreenPipe tries to
adapt an original file f, and performs the following check
isinstance(f, file) f is an original file object with file
is now our file method. This fails causing TypeError

nova-api exercises this

Fix up zmq to use the extended add signature

Having heard no problems relating eventlet and zmq,
I'm not going to dive in and drop random pataches against
it. If the 'Second simultaneous *er' crops up against
zmw then we at least now have the machinery to
address it.