ubik: log important messages at default log level

ubik: log important messages at default log level

Many important ubik messages (e.g., errors, warnings, sync state
changes) are logged at log level 5 (-d 5) or higher.  Many sites are
reluctant to run ubik servers at a logging level higher than the default
due to the large number of extremely noisy informational messages at log
level 5.  Therefore, many important log messages are never seen.

Instead, issue critical errors, warnings, and other important messages
at log level 0 so that they are always seen, even at the default logging
level.

In addition, disambiguate the two "I am no longer sync-site" messages by
adding a unique reason text to each.

Reviewed-on: https://gerrit.openafs.org/12617
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Reviewed-by: Andrew Deason <adeason@sinenomine.net>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
(cherry picked from commit 8b0e312d043d435f0e55c6dc14f5446ffedc7ce4)

Change-Id: I87425e78fb4f7fb1aa393b2f5b81ab34a71a38c4
Reviewed-on: https://gerrit.openafs.org/13906
Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
Reviewed-by: Andrew Deason <adeason@sinenomine.net>
Reviewed-by: Cheyenne Wills <cwills@sinenomine.net>
Reviewed-by: Mark Vitale <mvitale@sinenomine.net>
Reviewed-by: Marcio Brito Barbosa <mbarbosa@sinenomine.net>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>