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
Fix conf/origins/havana.yaml symlink

Change-Id: I38dee8cb5bc499e5103421bcf2a6db9a229b9480
Disable oslo-messaging component for havana-git

It is not needed there.

Change-Id: Ied6dbc3741cca620afddb4b6d1f3fd3dcf332d40