Support of regional endpoinds using Keystone v2

Handles the configuration region_name_for_services
with the keystone V2 authentication.

Change-Id: Ibba4d617937da8ba6018471e9614259e90409a47
Use ResourceDefinition when updating Load Balancer

Use a ResourceDefinition object to define the Load Balancer configuration
when Autoscaling updates it. This makes it consistent with the regular
stack update code, which now passes a ResourceDefinition instead of a
template snippet.

Change-Id: I717559257b01bd0eaf0f3da48fb64bf60dcb2f8d
Handle missing user_creds in stack.delete

In some cases concurrent or interrupted and resumed stack delete
operations will result in missing user_creds records referenced in a
stack. This may be the cause of race conditions between deletes
resulting in unexpected behavior and spurious failures.

Change-Id: I76f3f8803a4f9171223783a9c6eea0fc20280010
Related-Bug: #1306029
Implement NovaFloatingIpAssociation res updatable

Implement handle_update for NovaFloatingIPAssociation
resource, allows to update NovaFloatingIpAssociation with
new server_id and new floatingip_id.

Change-Id: I75d361e2f0381f50ab83b54d752ffc080fe337fa
Implements: blueprint handle-update-for-floatingip
Merge "Use ResourceDefinition when updating Load Balancer"
Merge "Handle missing user_creds in stack.delete"
Merge "Support of regional endpoinds using Keystone v2"
Merge "Implement NovaFloatingIpAssociation res updatable"