Some config options(interface_driver, use_namespaces) are defined
multiple times in ad-hoc way. It causes DuplicateOptError exception
when using those module at the same time. Right now the exception is
avoided in ad-hoc way by each executable. Those duplicated
definitions should be consolidated and treated in uniformed way.
This is the blocker for blueprint: l3-agent-consolidation
neutron.services.loadbalancer.drivers.haproxy.agent periodic_interval
conflicts with neutron.service one. Since there is no way to fix it
without changing existing behavior/default value, it is untouched for now.
Closes-bug: #1279769
Change-Id: Ifed79b7ee0033644854499416f8a2b22a20416fe
9af846caf7