moved xinetd dependency in percona module in order to permit the correct percona class deployment (before users, tables and grant configuration)

corrected percona variables: mysql_cluster_server as a String andwsrep_node_address rely on getvar instead on facts[]

added possibility of changing ip addresses of single database node. Requiring percona module > 1.0.0

added user grant for cinder, glance, neutron, nova and keyston on mysql cluster temporarily from localhost and haproxy settings for nova and neutron. Cleaned up other haproxy unused (commented)

modified database.pp profile, putting percona instead of galera. Ensured xinetd package installed and service started

Descrizione delle modifiche fin qui fatte
- files/heat-keystone-setup-domain
-- fix dell'import di oslo.config
- manifests/profile/database-client.pp
-- classe per l'installazione del mysql-client in locale; in sostituzione della classe manifests/profile/database.pp
- manifests/profile/keystone.pp; manifests/resources/database.pp
-- modifiche al file keystone.conf

- Modifiche alle altre classi per staccare Rabbit-MQ, CEPH, Percona, HAproxy, keepalived dalla configurazione dell'infrastruttura.

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

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)