The new -v option forces the progressbar, even in case the output
is not a terminal. This can be useful if the caller is an IDE or
wrapper which wants to scrape the progressbar from stderr and show
its information in a different format.
Signed-off-by: Miklos Vajna <vmiklos@frugalware.org> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>