[groff] Assume C99/POSIX conformance?

[Eric S. Raymond]

There's a lot of historical cruft in the groff source code that could
be removed (to improve maintainability, making the code easier to read
and modify) if we're willing to assume that all target platforms are
C99 and POSIX.1-2001 compliant.

I have been coding strictly to these standards since 2009 on GPSD and
NTPsec, two projects with much closer ties to the underlying OS than
groff, and never had a non-trivial port problem on either.  The
standards people won; modern toolchains are really good that way.

I've scoped the problem and I think it would take me only a day and a
half or so to do a cleanup pass on groff.  Any objections?
-- 
                <a href="http://www.catb.org/~esr/";>Eric S. Raymond</a>

Nearly all men can stand adversity, but if you want to test a man's character,
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        -- Abraham Lincoln