Replace all in-tree uses with necessary subset of <sys/{fb,kb,cons}io.h>.
This is also the appropriate fix for exo-tree sources.
Put warnings in <machine/console.h> to discourage use.
November 15th 2000 the warnings will be converted to errors.
January 15th 2001 the <machine/console.h> files will be removed.
not work on any real hardware (or fully work on any simulator). Much more
needs to happen before this is actually functional but its nice to see
the FreeBSD copyright message appear in the ia64 simulator.