Can anyone comment on issues below, arising from an attempt to merge
with the gnulib version of strftime?  It's specifically rms's change
which depends on __hpux rather than testing for sys/_mbstate_t.h, and
andrewi's changes involving USE_CRT_DLL and WINDOWSNT.  Jim's
suggestion about HAVE_TZNAME isn't relevant because that's actually
what HAVE_TZNAME means, and it turns out ms-w32.h defines it.  What
does USE_CRT_DLL mean, and does Windows always have the semantics of
it being defined?