Fio-plot

A lot of changes has been made

Fio plot

- Added a table for the 2D bar chart (-l) that shows steady state statistics (Fio feature)
- Changed the style of the Legend for 2D line charts (-g)
- 3D charts now support plotting bandwidth statistics in addition to IOPs and latency
- Ton of under-the-hood changes, made code cleaner, but also added some ugliness back in (sorry)

Benchmark script

- The benchmark script supports running a preconditioning run for SSDs
- The benchmark script supports the "steady state" feature that stops a benchmark when steady state is reached
- The script has been cut up into multiple files so it's a bit easier to work with the code

The following changes have been made:

- I've improved the README file by including command-line examples for every graph in the introduction.

- The 2D bar chart could only show iodepth performance for a particular numjobs value. With the -N option, we can swap this and show numjobs performance for a particular iodepth.

- There are some under-the-hood code improvements to make the code more consistent

- There is some code that scaled down labels for x-axis if those become too wide otherwise. It is still wise to trim them using the --xlabel-parent and --xlabel-depth parameters if possible.

The repo was about 50 MB due to .png files and tons of benchmark data in earlier commits. Those have been removed.

For some reason, I borked the calculation for the table width for the standard deviation and cpu-usage tables. Sorry for the inconvenience.

See details in releasenotes.md

See the releasenotes.md file for more details.