Adding thousands separators to the graphs

[MarcelWaldvogel]

Some of the numbers get very big, when measured in µs; I have had several seconds of errors in some cases. Then, keeping track of number of zeros in the ytics is hard.

Therefore, adding some form of thousands separators to the graph would be useful.

I already did try a few things, including switching to the %'f format and adding lines to graph-header:

• set locale "en_US.UTF-8" (apparently applies only to day/month names) and
• set decimalsign locale (mentions thousands separator, but does not seem to influence it)

Is this something that needs to be pushed upstream to gnuplot or is that something that can be fixed in chrony-graph?