Re: pg_resetwal tests, logging, and docs update

Hi,

> Here are updated versions of the remaining patches.  I took out the
> "FIXME" notes about the multipliers applying to the -c option and
> replaced them by gentler comments.  I don't intend to resolve those
> issues here.

The patch LGTM. However, postgresql:pg_resetwal test suite doesn't
pass on Windows according to cfbot. Seems to be a matter of picking a
more generic regular expression:

```
at C:/cirrus/src/bin/pg_resetwal/t/001_basic.pl line 54.
                'pg_resetwal: error: could not change directory to
"foo": No such file or directory
  doesn't match '(?^:error: could not read permissions of directory)'
```

Should we simply use something like:

```
qr/error: could not (read|change).* directory/
```

... instead?

-- 
Best regards,
Aleksander Alekseev