Use galera in HA all-in-one host group

This patch will use galera within the HA all-in-one host group. It also includes a custom puppet fact (galera_bootstrap_ok) that checks to see if any of the openstack databases exists. It can use this too bootstrap galera for a fresh deployment, in which case galera bootstrap will take place on the pacemaker control node.

Note that this depends on a previously merged patch that refactors the load balancer deployment such that haproxy will be up and running prior to any node trying to contact the database.