Bug#180753: base-installer: should show progress bar when installing

[Petter Reinholdtsen <pere@hungry.com>]

Package:  base-installer
Version:  0.016
Severity: wishlist

When installing the base system, instead of scrolling text across the
console, there should be a progress bar showing how much is left to
do.  It should also display how much time is left before the
installation is finished.

There is some code in boot-floppies (dbootstrap) to parse the output
from debootstrap and display a progress bar.  It should probably be
moved into base-installer.