[Michael Newcomb]

When joining with state transfer, the coordinator starts the flush, but
the joining member stops it. This might lead to an issue because as soon
as the coordinator casts the new view to everyone (and receives their
acks) he starts processing the next request in the queue without waiting
for the flush to be completed.

I noticed this because I got a 'retrying flush' without ever seeing "...
Running FLUSH...". So, flushInProgress is still true. The problem might
arise in that when it retries it sets force=true and that could possibly
cause a flush to start before the stop has been received.

Not sure it is an issue, but just thought I'd bring it up.