CBD-1349: Overall commit validation script

Change-Id: I711c852663c4ce893d7a89b3cea2993d21f51feb
Reviewed-on: http://review.couchbase.org/38511
Reviewed-by: Eric Limare <eric.limare@couchbase.com>
Tested-by: Eric Limare <eric.limare@couchbase.com>