MB-11821 rename upr to dcp in stats and logs

Change-Id: Ib2cf48190b2bf274f953b8da1b1cd1373de190c2
Reviewed-on: http://review.couchbase.org/39898
Reviewed-by: Michael Wiederhold <mike@couchbase.com>
Tested-by: Michael Wiederhold <mike@couchbase.com>