switch from humantime to jiff

[BurntSushi]

This PR bumps to jiff 0.2 and removes humantime in favor of jiff.

Back when I first contributed the change to move to Jiff
in #31, Jiff didn't have a way of formatting durations
like humantime does. But Jiff does support that
now.

One part I'm a little unsure about here is that prodash was still
trying to emit times even when local-time wasn't enabled, and it
was using humantime to do this. But now that Jiff is used for both
things, it probably doesn't make sense to have this fallback. (I think
it's also somewhat suspicious, since printing UTC time as if it were
local time is likely confusing.) In any case, I left it as it was,
except with using Jiff.

I tried running tests locally, but one of the tui rendering tests just
hung indefinitely for me.

[Byron]

Thanks so much for your continued and timely support, it's much appreciated! That's exactly what I was looking for when getting this PR ready for merging, so once again, perfect timing :D.

With these out of my system, make tests worked for me, and so did the monstrous cargo run --example dashboard --features="render-tui render-tui-crossterm render-line render-line-crossterm signal-hook render-line-autoconfigure progress-tree local-time" --.

I don't know if it was always so precise, but think that such details can be tackled at a time when displaying durations in the terminal becomes important.

Thanks again!

[Byron]

PS: I really like that the code became so much simpler thanks to the change!

[BurntSushi]

Nice! And yeah, from my read of it, humantime should have also shown similarly precise durations.

If and when you do want to tweak it, Jiff has a lot of options for rounding durations and controlling the largest/smallest units. Happy to field questions there!