Use the new qprogress() function in more places.

Use the new qprogress() function in more places.

qprogress() was introduced in the last commit and has smarter default
behaviour that automatically reduces progress output so we don't print too
many messages per second.  Various commands/etc were doing this in various
different ad-hoc ways, but let's centralize it all in one place.

Signed-off-by: Avery Pennarun <apenwarr@gmail.com>