Change installer to use postgres.

Note that more changes are likely needed to get installer back to fully working
using postgres.
Fix typo in ceilometer notifier constraint name
Merge pull request #402 from bcrochet/ceilo-constraint-fix

Fix typo in ceilometer notifier constraint name
Use account security from mysql puppet to remove defaults
Merge pull request #403 from bcrochet/galera-acct-security

Use account security from mysql puppet to remove defaults
add hostnames into /etc/hosts local to pacemaker cluster

*Motivation is that pacemaker prefers to use hostnames over IP's and
 this becomes a hard requirement for using the galera resource agent.
*Use the already existing parameters $lb_backend_server_names and
 $lb_backend_server_addrs.
*remove redundant parameter $pacemaker_cluster_members.
galera resource agent