cope with the new names and paths used by the netboot d-i packages.
When Internet connectivity was available, the installer fall back to
using wget to fetch d-i boot images, but when offline it require
-working packages to get it working. And ad the packages changed name
+working packages to get it working. And the packages changed name
from debian-installer-6.0-netboot-$arch to
debian-installer-7.0-netboot-$arch, we no longer pulled in the
packages during installation. Without our test suite, I suspect we