[PATCH 04/10] Require GNU make

[Tom Tromey]

Mike> i've just been looking at moving these to automake and not worrying about
Mike> the quality of the existing Makefiles.  although i'm not ready just yet to
Mike> move these ports over.

You may have difficulty with this because automake doesn't handle the
build/host distinction very well.  Like, there's no canned way AFAIK to
say that a given executable should be built for one or the other.

I tend to think it would be simpler to just reimplement the bits you
need.  Once you can rely on GNU make this kind of thing is pretty easy,
and less opaque than automake.

However, don't let me stand in your way.  And, I'm definitely in favor
of removing all the subdir configure scripts.

Tom