Docker doesn't seem to server images for 12.04 anymore.
Remove their repo from 12.04
Remove dead code of CrowbarUtils
Update docs for removal of crowbarutils.
Make the OS selection be the role default for ready state wizard.
Merge pull request #280 from galthaus/remove-crowbar-utils

+2 Remove crowbar utils
Merge pull request #291 from galthaus/get-ready-use-default-os

+2 Make the OS selection be the role default for ready state wizard.
Merge pull request #255 from galthaus/docker-12-04-cleanup

+2 Docker doesn't seem to server images for 12.04 anymore.
Add demo-mode to KVM.

To use it:

1: Create an admin disk by running kvm-admin with --create-image <file>
2: Setup the admin node as normal.
3: Once the admin node has converged:
   1: rm /etc/udev/rules.d/*persist*
   2: halt
4: After the system has halted, kill the kvm-admin script.  This
   will cause the disk the admin node was using to be converted into
   a compressed qcow2 image stored in <file>
5: When you are ready to run the demo, run kvm-admin --demo <file>
Make kvm-admin fail when passed an invalid option.

Better to do this instead of spinning forever.
Fix stupid typo