Neutron packaging improvements

- don't package rootwrap lists for plugins twice;
- package all *.ini files from /etc/neutron to openstack-neutron
  - they all are used by binaries in neutron package
  - this fixes build for neutron from stable/havana git branch

Change-Id: I96ee682d7d2aaea71b97f77111b7a6c61216cbe5