FYI: reduce noise from dpkg in D-I log

[Frans Pop <elendil@planet.nl>]

I've just submitted a patch against dpkg to allow us to suppress the 
distracting extra output we now get in the logs due to progress updates 
while dpkg reads its database.

See http://bugs.debian.org/539617 for details.

If you have any comments from a D-I PoV, then please let me know.

Cheers,
FJP