Strip out file path and extension for prettier benchmark names in the HdrHistogram report.

[kellabyte]

The current [HdrHistogram] R script uses the full filename path and extension as the name in the legend. I think it would be a lot prettier to strip those out.

Figure 1. Example of a latency distribution graph showing filepath + filename as benchmark names.

Here is the R script that needs the changes.

Rscript ./plotting/hdr_histogram.r ./results/samples/nanotime.histogram ./results/hrtime.histogram 6 results/time_p999999.png

Figure 1. Example of generating the HdrHistogram latency distribution graph.

Here are the instructions for generating reports using the R scripts against some pre-made benchmark results provided to make working on our R scripts simple for new people.