add grub

Not sure why this was missing from the susestudio export.
allow pre-population of /srv/tftpboot repos in overlay filesystem

This script will pre-populate /srv/tftpboot/repos in the overlay by
bind-mounting the repository mirrors from the image-building host.
reduce grub prompt time-out to 3 seconds
tidy up config.sh
add OVF file for admin appliance

This was generated manually in VirtualBox and then exported as OVF.
add metadata.json
metadata.json: change vdisk size to 16GB
import Vagrantfile created via `vagrant package`
automate building of boxes from vmdk built by kiwi
initial stab at a multi-VM Vagrantfile for the whole cloud
add box catalog metadata JSON document

This is as described at http://docs.vagrantup.com/v2/boxes/format.html
and allows us to `vagrant box add cloud-admin3.json` and get the box
with the right version number.