gvfs-copy: Make the progress output usable
gvfs-copy: Make the progress output usable

Rather than spamming the screen with output, rate-limit the updates and
make them display over each other.

https://bugzilla.gnome.org/show_bug.cgi?id=637543

gicmo/gvfs,gicmo/gvfs,gicmo/gvfs,gicmo/gvfs