Changes to allow Hugs to be built with mingw32, not cygwin.  Also,
updates so that DietHEP works properly for mingw32.  Most changes are
trivial (assert --> ASSERT), etc.  For hugs, have deleted queries
about the width of a terminal window, and so the printing of dots
as progress indicators is gone too.  No great loss.  Zapped various
other out-of-date platform-specific junk in machdep.c.