Progress output

[weefuzzy]

adds

• a fixed width progress output (no fancy terminal progress bar, but hopefully parse-able by both people and machines),
• Writing <X> during the output rendering (as this can take a while as well).

This is based on the work @jamesb93 did in his PR #2, mostly just tweaking the output formatting and merging updates back in.

This, hopefully, makes things feel a little more responsive. Feedback sought (incl. @jamesb93 – can you try with ReaCoMa and confirm (or not) that you can work with this).

I guess if it turns out people are doing a lot of shell scripty stuff and don't want the noise, we can add a --quiet switch.

[jamesb93]

I will take a gander at this now!

[jamesb93]

On really big files you won't see any progress output while its doing the internal copying. Maybe it could post 0% straight away? Minor pick though, otherwise it looks great!

[tremblap]

it works. a strange behaviour, when one runs it with erroneous arguments, like fluid.hpss all by itself, one get:

./fluid-hpss
100%
Input buffer not set

getting the 100% before is not ideal, no?