Feature Kvm Select Iso List

• the old field now named Boot image list has to be correctly renamed
• Boot image list shall not drop access to default image
• implement Boot image
• images shall be available on boot as:
  • Boot image
  • Boot image list
  • the default one (it's a change, previous implementation, not released yet, was replacing it)
• tests has to be extended
• add SR developer howto about procedure to update those images
• check deeper JSON Schema validation
• really support cluster, seems the images ended up in the frontend configuration instead of the VM, and that's not what we wanted
• warning KVM supports only 4 -drive media=cdrom anyway, otherwise exists with message machine type does not support if=ide,bus=2,unit=0
  • it means that maximum 3 cd can be given from Boot image and Boot image list, such promise shall be used, as otherwise KVM does not start at all
• reconsider naming of the fields (ids)