CBST-13: push atop+kvlatency to cbfs

pull stats from atop dbs per-node along with latency data for final report
generation in system-test.

Change-Id: Idbfb633b81240c234c3ccefa839cd9b290b18cfc
Reviewed-on: http://review.couchbase.org/30531
Reviewed-by: Tommie McAfee <tommie@couchbase.com>
Tested-by: Tommie McAfee <tommie@couchbase.com>