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

Macro argument quoting does not prevent recognition of punctuation
and of called macros.

This bug affects almost all macros, and fixing it simplifies the
code. It is amazing that the bogus ARGS_QWORD feature got implemented
in the first place, and then carrier along for more than eight years
without anybody ever noticing that it was pointless.

Reported by Leah Neukirchen <leah at vuxu dot org>, found on Void Linux.

Multiple fixes with respect to in-line macros:
* .No selects the default font; relevant e.g. in .Bf blocks
* no need to force empty .Li elements
* closing delimiters as leading macro arguments do not suppress space
* opening delimiters at the end of a macro line do not suppress space
* correctly handle delimiter spacing in -Tman
As a side effect, these fixes let mandoc warn about empty .No macros
as requested by bentley@.