Setup rabbitmq to use keepalives (https://bugs.launchpad.net/nova/+bug/856764) & rewrote its ha-all policy

Fixed various timeout values, keep-alive parameters & "backup" option for HAProxy - Galera to avoid unexpected socket closes, failed SQL transactions, etc.

- Network configuration (such as IP addresses, default gateway...) shall now be set up beforehand. It is not done by the base class anymore. We now simply use the IPs from configured interfaces.
- Reworked +Fixed some things in Neutron networking services too.

Removed database_idle_timeout as it is not necessary anymore since 6f05de06 and updated two HAProxy IP addresses

Added Keystone, Glance, Cinder, Nova, Neutron API services & Added Galera/RabbitMQ to Load-Balancing.
(The commit is pretty big, sorry about that, I'm still bootstrapping the project)