Fix/avoid measurement errors due to coordinated omission [JIRA: TOOLS-114]

[slfritchie]

See also: brianfrankcooper/YCSB#214 (though that branch appears to be merged into the https://github.com/YCSB/YCSB repo now, despite the status of that ticket)?

It would be awfully nice if we could have basho_bench avoid measurements due to coordinated omission. Gil Tene and others have been very helpful in pointing out this problem in many tools. YCSB has recently fixed it; b_b should do so also.

[slfritchie]

This issue is still on the todo list. No estimate for implementation time, however. PRs are welcome. ^_^