Hurd patches for installer/build

[Jeremie Koenig <jk@jk.fr.eu.org>]

Hi, these are the patches I'm using to build my Hurd d-i images.

I believe the first five should be considered for inclusion:

[PATCH 1/7] Fix the generation of pkg-lists/standard-udebs
[PATCH 2/7] Override $(genext2fs) in config/hurd.cfg
[PATCH 3/7] Fine-tune the Hurd configuration
[PATCH 4/7] Add /lib/ld.so and /servers/exec to Hurd initrd's.
[PATCH 5/7] Include a BDF font on Hurd images.

The last two are clearly not suitable and I include them for your
information only:

[PATCH 6/7] Temporary workaround: preseed file for Hurd images
[PATCH 7/7] Work around my laziness wrt. signing the Release file for my repository.

Please let me know of anything I could improve!