Remove the redundant StepRemoveDevices and rely on the cleanup to be handled by:
* StepAttachParallelsTools.Cleanup
* StepAttachFloppy.Cleanup
* stepAttachISO.Cleanup
New config option:
reassign_mac (boolean) - If this is "false" the MAC address of the first
NIC will reused when imported else a new MAC address will be generated by
Parallels. Defaults to "false".