Use kpartx if partition device doesn't exist

If the loop partition isn't created as a device by the kernel, go ahead and use
kpartx to create the device.

Change-Id: I53290b7724d0cb45a1fc9225ec096025db8978dd
Remove a device mapping, then let the loop device get removed

Change-Id: Ie1eb621ff56688208421d0115547f127a3c7fd56
Call sync before unmounting keeps the mount from being busy.

Change-Id: I9d5a1f092fd8f3ae1c14de03dd516203baab4da3
Add rhel installation element

If you want to have the installation update packages, you'll
need to register the system log in to rhn and subscribe to an
available subscription.
export RHSM_USER to your rhn username
export RHSM_PASSWORD to your rhn password

To get the qcow2 image, log into rhn.redhat.com and download the
image from
https://rhn.redhat.com/rhn/software/channel/downloads/Download.do?cid=16952
Then export DIB_CLOUD_IMAGES to whereever you're hosting the qcow2.

Change-Id: Idb547f4ffe75514b1e3f6b34f5f347493b132925