Print the number of errors in the progress report
$ ./wget2 example.com/wget.html
[0] Downloading 'example.com/wget.html' ...
HTTP ERROR response 404 Not Found [example.com/wget.html]
$ ./wget2 example.com/wget.html --progress=bar
wget.html 100% [===========================>] 606
[Files: 0 Bytes: 606 Redirects: 0 Todo: 0]
Although reading "Files: 0" you know there was a problem downloading 'wget.html', I think it can be confusing. It would be nice to report the user the number of errors while downloading the URL queue.