Regenerate nova.conf.sample

Fix generate_sample.sh script so that we include options from the bin/
scripts too. In order to make this work, sync a zmq-receive fix from
oslo-incubator to delay parsing its config file.

Change-Id: Ia3f9083b2ebc16425dbad8a2a55c2d45f1ff2be3
Merge "Regenerate nova.conf.sample"