This feature was originally meant to redirect verbose logging to *any*
fd, but it now only supports writing to stdout or stderr, and defaults
to stderr.
Redirecting to stdout isn't very useful and complicates the code, so
just remove it and always use stderr.
* Unify the line endings to the Unix style (LF only).
* Fix (where possible) or remove broken links.
* Improve the documentation.
Fix or remove broken links (depending on whether I could find a
working version of the resource).
Change all links to use HTTPS instead of HTTP.
Unify the capitalizations (e.g. uppercase abbreviations, capitalize
proper names and downcase other words).
Fix or improve some parts of the text, clarifying what is meant.
Improve some parts of the program examples (e.g. only use root
privileges where really required).
