message: Print a line per downloaded crate
  This commit brings back the old one-line-per-crate output that Cargo's
  had since the beginning of time but was removed in This was
  requested on our [users forum][1]
  [1]:
diff: @@ -540,10 +540,10 @@ impl<'a, 'cfg> Downloads<'a, 'cfg> {
  };
  // If the progress bar isn't enabled then we still want to provide some
  - // semblance of progress of how we're downloading crates.
  - if !self.progress.borrow().as_ref().unwrap().is_enabled() {
  + // semblance of progress of how we're downloading crates, and if the
  + // progress bar is enabled this provides a good log of what's happening.
  + self.progress.borrow_mut().as_mut().unwrap().clear();
  self.set.config.shell().status("Downloaded", &dl.descriptor)?;
  - }
  self.downloads_finished += 1;
  self.downloaded_bytes += dl.total.get();
  