Ensure Neutron DB is populated

- Create symbolic link to have /etc/neutron/plugin.ini
- This file is used to synchronize the database

In that way, the command to populate database is generic to all plugins.

Fixes-Bug #1275688

Change-Id: If320b4fa5682245ac2cc9b4a9f05cf02dadc84c0
Signed-off-by: Emilien Macchi <emilien.macchi@enovance.com>
(cherry picked from commit fea38195c6ede5d33b935701396534ef4757dffc)
Fix FWaaS race condition

The current FWaaS manifest suffers from a race condition: it may
attempt to configure the FWaaS service before the Neutron packages
on which it depends has been installed, and before the
/etc/neutron directory exists.  This leads to errors on the first
catalog run, and the FWaaS service doesn't start.  The errors
go away on the second catalog run since by then the requisite
directory exists.  This patch adds ordering such that the packages
on which the FWaaS service relies are installed before the FWaaS
service is configured.

Change-Id: I174cf06b9e8355bfe499b23f390d4078dc670e72
Closes-Bug: #1287554
(cherry picked from commit cfedc81cb60cabdbb31f3809e9d56a54d771458b)
Merge "Fix FWaaS race condition" into stable/havana