updated preemptive-kernel patches for 2.4

Patches for 2.4.20, 2.4.20-ac1, 2.4.21-pre1 and older kernels are available at:

http://www.kernel.org/pub/linux/kernel/people/rml/preempt-kernel/

This is just a resync with the new kernels; the core of the patch is unchanged.

Enjoy,

Robert Love