Attached is a snapshot of a basic nonlinear implementation.  It's similar
to the one Daniel Phillips did a couple of years ago.  So far it works on
base x86 machines.  Still to be done is to port to other architectures and
roll support for discontigmem into it.

My apologies for not moving this forward to the latest -mm.  It's just
getting too hard to keep up with akpm :)

Dave McCracken