- added support for EFI in live ISO images. In order to create
  a syslinux plus EFI (grub2) live ISO use the following type

  <type image="iso" firmware="efi" .../>

  hybrid support for EFI live ISO's requires the new isohybrid
  tool which could also write a gpt into the isoheader.
- allow archives in the bootsrap section to allow build
  of images of older distributions
- fix architecture handling for ProductPackages, allow a
  comma separated list of architectures