[Libvirt-cim] [PATCH 0 of 2] CDROM Support

This is not how I envisioned (or started to implement) CDROM support, but I think this is the better way. The second patch is the bit I sent before that makes xmlgen not clobber the device property. The new first patch adds the ability to set this in the Disk RASD on create, which gives us our CDROM support. If this is okay with people, I can follow it up with making Virt_Device expose a KVM_CDROMDrive instead of KVM_LogicalDisk for devices so configured.