Fix nova-compute not starting properly after reboot

Intermittent problem caused by time change after kernel load.
https://github.com/djoreilly/quantum-ansible/issues/3
Change default logging from DEBUG to INFO
Workaround dhcp agent keeps respawning dnsmasq

The default dhcp_agent.ini does not have a root_helper. Adding one here
allows the ns proxy to start in dhcp ns and agent can function normally.
https://github.com/djoreilly/quantum-ansible/issues/1