Fix up nova-compute.conf to let Quantum manage the firewalls.
Zap redundant firewall_driver line in nova.conf
Don't attach smoketest instances to the floating network by default.

Instead, we will create them later on via the usual apis.
Merge pull request #141 from VictorLowther/pull-req-release-pebbles-master-d2bf78a4d50c026a2d9d3e918e8280c70b543797

Make progress in getting the quantum metadata agent functional. [1/2]