hotplug startup should be verbose when booting in recovery mode

[Matt Zimmerman]

This is extremely valuable for debugging "hangs at boot during hotplug startup"
bugs.

It would be ideal if $VERBOSE would be forced to 'yes' in this case, but given
the implementation, this would be tricky without adding shell code to
/etc/default/rcS

[Martin Pitt (pitti)]

My preferred choice would be to test for single user mode in /etc/default/rcS
and set VERBOSE=yes in it in that case. However, that file is not a conffile, so
we can't change it in an upgrade, and we don't have /proc/cmdline available when
/etc/init.d/rcS runs, so for now we have to restrict this to hotplug.

So we could apply this idea to /etc/default/hotplug and set QUIET to no. This is
not a conffile as well, though, so upgrades would get funny.

But why do we need to touch /etc/init.d/rcS for that?

[Matt Zimmerman (mdz)]

Rather than changing /etc/default/hotplug (which shouldn't contain shell
commands, only variable settings), we should set the default for QUIET based on
/proc/cmdline in /etc/init.d/hotplug, and allow /etc/default/hotplug to override it

[Martin Pitt (pitti)]

 hotplug (0.0.20040329-22ubuntu9) breezy; urgency=low
 .
   * debian/hotplug.init: Only default to QUIET if we are booting in normal
     mode; be verbose in single user mode. (Ubuntu #11118)