[Feature idea] : add average speed + elapsed time

[benintech]

Hi,
Very nice patch, really improves cp and mv a lot.

Until now I used Midnight Commander to do large copy or move operations, because of the lack of progress bar. Now I switched over to your patched versions.

There are two informations that I am missing during a copy/move operation, though:

• The average speed since the operation started (it only shows the current speed of the file being currently copied/moved)
• And maybe the elapsed time since the operation started

It would be nice if you could add those infos.

[jarun]

Feel free to raise a PR. I don't have the bandwidth to add features anymore.