Changes

Summary

1. cpu time is somewhat redundant for threads=1; tuned output;
2. clarified description vs. file name;
3. tuned output;
4. clarified types;
5. more operations;
6. more uniform charts; tuned headings;
7. always show ml_timing -- in another chart;
8. removed threshold: redundant due to sorting;
9. tuned output;
10. parallel gnuplot invocation;
11. more HTML output;
12. clarified explicit Build_Status.Data operations; more HTML output;
13. more operations; tuned;
14. more uniform threads value, notably for Pure session;
15. tuned;
16. added option verbose for SQL source;