Instance delete should check for 'DELETED' status

Currently in Instance.py check_delete_complete method is waiting
for 'NotFound' exception. This change is to wait for 'DELETED'
state to speed up the resource/stack delete.

Closes-Bug: #1243389

Change-Id: I09712f548f40bb13c2b322550007f5bd30dfb3e2

heat/engine/resources/instance.py

@@ -483,6 +483,12 @@ class Instance(resource.Resource):
 
             try:
                 server.get()
+                if server.status == "DELETED":
+                    self.resource_id_set(None)
+                    break
+                elif server.status == "ERROR":
+                    raise exception.Error(_("Deletion of server %s failed.") %
+                                          server.id)
             except clients.novaclient.exceptions.NotFound:
                 self.resource_id_set(None)
                 break