Add more command stats

Change-Id: I9497b8cc8419a9966634387097fb529f9e10d835
Reviewed-on: http://review.couchbase.org/41805
Reviewed-by: Michael Wiederhold <mike@couchbase.com>
Tested-by: Michael Wiederhold <mike@couchbase.com>
Merge remote-tracking branch 'membase/3.0.1'

* membase/3.0.1:
  Add more command stats

Conflicts:
	daemon/timings.h

Change-Id: I600288ab7c1eee503c714e40875a7cb6eb61ed8d