Use attribute from rabbitmq node to get rabbitmq IP address

The rabbitmq cookbook saves the IP address used by rabbitmq to listen,
so no need to do some fancy thing to get it.
Use helper from database cookbook to get database IP address

This way we're ready for when HA will be used for database.
Merge pull request #159 from vuntz/db-ha

Get ready for HA in database and rabbitmq
Update db password migration script to remove node attributes

On update, we want to use the db password from the proposal / role, and
not the one that might have been generated on the node (through the
cookbook). As the password is a "normal" attribute on the node, but a
"default" attribute on the role, the old one from the node is used.
Which means we really need to remove it to get the new one used.

To minimize config changes, we actually import the password from one
node (which should be good enough in most cases as we allow only one
cinder proposal, so only one node should have the password).
Use new synchronization helpers to avoid races when deploying with HA

There are a number of possible races when deploying cinder for the
first time:

 - when creating of the database / database user
 - when registering the endpoint and creating users in keystone
Manage cinder-api and cinder-scheduler with pacemaker

We create the primitives/group/clone resources (protected with
crowbar_pacemaker_sync_mark) and we use the
Chef::Provider::CrowbarPacemakerService service provider.
Check for unclaimed drives in disk-based deployment
Merge pull request #160 from vuntz/drop-db-node

Update db password migration script to remove node attributes
Fix deployment element path
Modify validation message to mention volume type
Merge pull request #161 from vuntz/sync-marks

Use new synchronization helpers + manage services with pacemaker
Update drive validation message
Fix the wording
Add insecure flag to keystone_authtoken config when required
Merge pull request #163 from rhafer/keystone_insecure

Add insecure flag to keystone_authtoken config when required
Check for cinder owned disks in cinder-volume validation
Fix letter capitalization
ha: Follow convention for pacemaker resource naming
ha: Do not pass is-managed / target-role meta when creating resources

We are happy with the default values.
Merge pull request #165 from vuntz/ha-convention

Update pacemaker resource names + other conventions for HA