Auto-update packer images to Jenkins via a change to Gerrit when ever a new image is built:

1. Get a list of images from the releng/builder repository
2. Search openstack cloud for the latest images available
3. Compare the time stamps of the new image with the image in use
4. Update the image to the config files and yaml files
5. Push the change to Gerrit

Move the changes to global-jjb, this is something that would be useful to other LF projects.