Shorten axis ticks if applicable

[jzillmann]

This is coming from https://github.com/jzillmann/gradle-jmh-report/issues/2.

If the scores are very large numbers like in

Then we could shorten the x-axis ticks with a magnitude label, e.g. 35M, 70M, ...

[jzillmann]

For single run x-axis and multi-run y-axis the ticks are now displayed more human friendly:

• 10000 => 10k
• 1000000 => 1M
• etc..