Up the default number of index histograms, but keep it fixed for the existing tests.
Add a duty cycle to index statistics scanning.
Get time limit from config service.
Move responsibility for index statistics warnings into the service and avoid repeating them for the same index.
Trigger background scan when enabled.
Address review comments.
merge MMcM: Some index statistics related improvements

Merge pull request #5 from MMcM/akiban-server/index-statistics
https://github.com/FoundationDB/sql-layer/pull/5