* Use curses. Darwin doesn't have termcap.
* Add __APPLE__ to system.h to define necessary macros.
* Replace __{Free,Open,Net}BSD__ with __UNIX__ in language/language.c.
It worked on *BSD, but not correct logically.
XXX -no-cpp-precomp issue isn't fixed yet. I think we should fix it in
XXX generic way.
rewritten. Allows for USA/non-USA support via the familiar USE_RSAREF2
mechanism, and significantly cleaned up. Does not attempt to fall back to
$HOME/.pgp for keys as in the FreeBSD port, as other programs already
require PGPPATH to be set.