``Disable'' a.out 'make world', as per flag day notification on current and

``Disable'' a.out 'make world', as per flag day notification on current and
committers.  A 'make aout-to-elf' is strongly encouraged.  This isn't quite
the end of the line for people who have a real problem with updating yet,
but we've got to get this over and done with.  Yes, it's bound to be a
couple of bumpy couple of days.