Build OpenStack packages from custom specs

Maintain spec files for OpenStack packages. Start OpenStack daemons
as native system services under different users. Write configuration
to /etc.

Implements: blueprint different-openstack-users
Implements: blueprint purge-config
Implements: blueprint package-novnc

Change-Id: I454c1e88011c75997d879bf8b90cd87c8db3f123
Add Openvswitch component

Change-Id: I39fb2d91fc07ff349eeb8284c7cd592d30487b85
Drop new unused tags in git repos

openstack.common.setup can report version incorrectly
(several version instead of one). This happens when
several tags contain the commit.

Solution: remove all extra new tags.

Fixes: bug #1190588
Add build-openvswitch.sh tool