Description of problem:

The openstack-nova-compute package should require: bridge-utils.  Without this package, the compute service will start correctly but new instances will fail to boot with the following error in the compute.log:

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2013-11-18 10:56:39.693 12912 TRACE nova.compute.manager [instance: bd1ff58e-53df-4c1f-9781-3a98ee62adaa]   File "/usr/lib/python2.6/site-packages/nova/openstack/common/processutils.py", line 178, in execute
2013-11-18 10:56:39.693 12912 TRACE nova.compute.manager [instance: bd1ff58e-53df-4c1f-9781-3a98ee62adaa]     cmd=' '.join(cmd))
2013-11-18 10:56:39.693 12912 TRACE nova.compute.manager [instance: bd1ff58e-53df-4c1f-9781-3a98ee62adaa] ProcessExecutionError: Unexpected error while running command.
2013-11-18 10:56:39.693 12912 TRACE nova.compute.manager [instance: bd1ff58e-53df-4c1f-9781-3a98ee62adaa] Command: sudo nova-rootwrap /etc/nova/rootwrap.conf brctl addbr qbre0460db5-bc
2013-11-18 10:56:39.693 12912 TRACE nova.compute.manager [instance: bd1ff58e-53df-4c1f-9781-3a98ee62adaa] Exit code: 96
2013-11-18 10:56:39.693 12912 TRACE nova.compute.manager [instance: bd1ff58e-53df-4c1f-9781-3a98ee62adaa] Stdout: ''
2013-11-18 10:56:39.693 12912 TRACE nova.compute.manager [instance: bd1ff58e-53df-4c1f-9781-3a98ee62adaa] Stderr: '/usr/bin/nova-rootwrap: Executable not found: brctl (filter match = brctl)\n'