Messages of the -Wbase level now print STYLE:. Since this
causes horrible churn anyway, profit of the opportunity to stop
excessive testing, such that this is hopefully the last instance
of such churn. Consistently use OpenBSD RCS tags, blank .Os,
blank fourth .TH argument, and Mdocdate like everywhere else.
Use -Ios=OpenBSD for platform-independent predictable output.

style message about missing blank before trailing delimiter;
inspired by mdoclint(1), and jmc@ considers it useful

Right after .Fl, a middle delimiter triggers an empty scope,
just like a closing delimiter. This didn't work in groff-1.15,
but it now works in groff-1.22.

After being closed by delimiters, .Nm scopes do not reopen.

Do not suppress white space after .Fl if the next node is a text node
on the same input line; that can happen for middle delimiters.

Fixing an issue reported by jmc@.