- fixed return value of setupBTRFSSubVolumes if no volumes are configured
- removed use of grub2-efi for openSUSE 13.1, the package
  was dropped and instead the following grub2 packaging
  schema exists:

  grub2             => grub tools
  grub2-x86_64-efi  => grub efi modules 64bit
  grub2-i386-efi    => grub efi modules 32bit
  grub2-i386-pc     => grub bios modules