Fix for CES-401: Quantum networking not recovering from compute node reboot

Symptom: When a compute node is rebooted, quantum networking fails for all
VM instances that are hosted on it.

Resolution: This is a known issue with quantum.  An OVS cleanup utility
was added to resolve this.  The utility needs to be run on the compute
nodes on bootup.

See:
https://github.com/openstack/neutron/commit/43ece8fb4c1bf77b662d28fa3bff42342b2a7a41
http://fedoraproject.org/wiki/Quantum
Merge pull request #135 from cdearborn/pull-req-release-roxy-master-a27319e68200c19ebd1dfa30be5268151359ba66

Merging fix for CES-401 from mesa-1.6.1 into roxy [1/1]