bozo: retry start after error stops

After a bnode is stopped because of two many consecutive exits
delay for some time and attempt to start the bnode again. Countine
to retry on each error stop, doubling the delay for each retry
attempt until a maxium number of attempts.

Reviewed-on: http://gerrit.openafs.org/5534
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementix.org>
(cherry picked from commit 170ce3db8a32c2b5df68ada3e84ecdaa98785e71)

Change-Id: I4f3863c31318ba9c5950ef74ec0a04b31decfebb
Reviewed-on: http://gerrit.openafs.org/9571
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>